Crypto Academy Season 3 Beginners' course - Task 2: Blockchain, Decentralization, Block explorer

in SteemitCryptoAcademy3 months ago (edited)



Introduction to Blockchain

My dear students, today I will try to tell you a very basic thing about Blockchain in very simple words. As you know the word blockchain is being used a lot on the internet at the moment and especially in the cryptocurrency market. If we consider the word blockchain, it is a combination of two words. Such as Block and Chain. A block is a place or box containing information. A box in which all information is stored, and from a chain such as a chain of information blocks that are connected to each other through an organised chain.

And when a block becomes a chain with the previous block, it means that the data in all the blocks connected with the chain is verified and it is now impossible to make any change in it. That's how the word blockchain came into being.
image source

In very simple terms, a blockchain is a chain of blocks in which information is stored.

The blockchain is like the distributor ledger. Therefore, the data in the blockchain is safe in every way.

Changing or altering store data in a blockchain is an impossible process. So we can call blockchain the safest distributor ledger.

So we would say that blockchain is a safe and secure online distributed system in which we can store all kinds of information. But at the moment most blockchain use is being seen in the cryptocurrency market.

Dear students, blockchain is a decentralized system and does not have the party of middle man and operates under P2P system. In a nutshell, blockchain is defined as an online distributed system in which we can store any type of information and that information can be viewed and verified everywhere by thousands of nodes around the world. And in the blockchain the information is stored inside the blocks and the blocks act as a registry folder.

When one block is filled with information, the system creates another block. And thus the new block becomes a chain with the previous block and thus the blockchain comes into existence from the previous and newly formed block.

Each block has three basic components and we can call them factors. And based on these three elements, we can verify the information in any block.


Let me tell you a little bit about these components in simple words

Data :

Data is present in each block. And that data gives us all the information. If we talk about cryptocurrencyb, the data inside a block provides us with this information. How much money was sent to which man by which user, when and how much money the person to whom the money was sent had before and where the money came from. Thus all the information about the sender and the recipient is contained within the block and it is impossible to change or edit this information.



A very important element of a blockchain is a block hash. Hash is a very unique code that varies from block to block. We can also say that Hash is the identification number of any block. The way humans have fingerprints. This way you understand that Hash is the finger print of any block.

And we can only verify the information inside a block with this hash code whether the information contained in the block is correct or not. Suppose the hash code of a block is Ah346drY25, then it means that this hash code will act as the identification of the relevant block.

Since the blockchain operates under a decentralized system, all the blocks in the blockchain are formed in a decentralized manner within which any change is impossible.

Previous Block Hash Code:

As I have told you that the example of Blocks is like a folder or register and when a register or folder is filled with data then we need a new folder or register to store more information like this in Blockchain.

Also, when data is filled inside a block, a new block is created to store more information and thus when a new block is created, the hash code of the previous block is entered in the new block so that it exists in the new and previous block.

Have access to information In this way, the new block and previous block is connected to each other in the form of a chain by the previous hash code, thus forming a Decentralized blockchain.



Dear students as we have read in the definition of blockchain that blockchain is a system that works under a decentralized system and it is impossible to change the information inside the block in any way. So with that in mind, I will try to explain to you what decentralization is and what its benefits are.

Decentralised refers to a system in which every user is empowered and autonomous in decision making. The decentralized system has no center but every user who is connected under the Decentralization system is autonomous and empowered to run his work and business in every way.

In a decentralized system, everyone enjoys freedom of expression. Thus, it was found that decentralized is a system in which every person working is empowered in his or her work and everyone from top to bottom is free in their decisions.

source image

If we search for the meaning of decentralization in a dictionary or on the Internet, we find these meaning

the transfer of control of an activity or organization to several local offices or authorities rather than one single one.Online Dictionary

If we try to understand the above definition in simple terms, it means to devolve power to the lower level and to empower and enable everyone who is associated with any decentralized system. That he/she can work in the system with full authority and not to give all the control in the hands of a single person.

Such a contradictory system of decentralized is called a centralized system. Centralized is a system in which the powers are vested in one central body and all powers are vested in that central body. And in this centralized system all individuals or users are bound to implement the decisions of the central body.

In short, in a centralized system, all the options are with the central command, while in a decentralized system, all the options are with the user and each user has a central position. To illustrate this further, I try to illustrate.

Suppose you want to do business in a centralized system, then you will be bound by the decisions of the central authority in every way to run your business in a centralized system. You will be bound by the decisions of the Central Authority to carry out all the transactions, buy and sell, payments and receipts that are necessary to run a business, even for the transfer of your invested capital.

The center will be subject to authority and you will not be able to run the business as you wish. Examples are amazon and Daraz. Thus, if you are a writer and want to write articles on various topics, you will not have full freedom of expression on centralized social media and if your writing is against the rules and regulations of the relevant media, then centralized media will close your accounts. can ban Clear examples of this are facebook, twitter and youtube.

Conversely, if you do business under a decentralized system, you will be fully empowered to run your business and you can make timely decisions in case of profit or loss.

You will not be bound by the central authority in the transfer and collection of money during business and thus if you are a writer or a journalist you have complete freedom of expression on decentralized media and no one can block your writing or voice.

And the best example of decentralized media is steemit social media which is working under a fully decentralized system.

How it is possible that in a centralized system all the powers are transferred to one center authority whereas in decentralized it does not.

One question that may arise in the minds of all of you students is how it is possible that in a centralized system all the powers are transferred to one center authority whereas in decentralized it does not. It is very easy to understand. Suppose you are creating your business account on a centralized website.

So at the time of registration you are transferring all your information to the server of this company. Even all your data is stored on this company's center server and the company will block your access to its server whenever it wants.

In this centralized system you are working on a server and it The owner of the server can block access to it whenever he wants. The most popular social media are facebook, twitter and youtube, so when you create your account on these social media .

your account operates from the main server of these site and thus when you take action against these organizations or against the rules. These closes your account because all your activities are performed in a centralized system connected to a center server.

In a decentralized system, the user's data does not operate on a center server, but in a decentralized system, thousands of computers combine to form a decentralized network, and in a decentralized system, each computer serves as a server.

And all the computers connected to this system are called nodes. That is why in a decentralized system, users' data is under their control. And third party intervention is impossible. And no single person can access any user's data. That is why when we define a blockchain, we say that a system in which information is stored under a decentralized system and changing or editing the information contained in the block is an impossible process.


In what areas of life can a decentralized blockchain be helpful?

A decentralized blockchain system can be helpful in many areas of life in general. The following areas are.

Health Sector

First of all, a decentralized system can improve the health sector. Because at the moment a patient is undergoing continuous treatment and he has to consult a doctor from different cities and countries for his treatment, then Decentralized blockchain can store complete data of a patient's disease and thus Through the health blockchain system,

all doctors of the world can check the patient's data. In this way, the complete record of medicine can also be stored under this system. Thus a transparency in the world's health system can be brought about thanks to this system.

land revenue

The second most important sector is land sales and records. And using blockchain technology, all land records of any country can be stored on decentralized blockchain. In this way, the element of corruption and fraud in the sector can be completely eradicated.

Because the land of many people is occupied by powerful people by occupying it and by producing fake documents, the land of poor and weak people is seized. In order to bring transparency in this sector also, land revenue blockchain can improve this system all over the world. And counterfeit transactions in this sector can be eliminated.

Politics and elections:

Politics is for the promotion of democracy in every country and different people in each country participate in the elections but the results of the elections are not recognized and various allegations are leveled against the opponents. Electoral rigging and fraud can be completed vanish by holding elections through decentralized blockchain because whatever vote is cast on the blockchain. It will be impossible to transfer it to anyone else. ?

Bank In addition, the banking sector can be fully shifted to the blockchain to bring speed and transparency in transactions.

Currently, cryptocurrency transactions are growing rapidly in all countries of the world. Therefore, two types of crypto trading systems are currently being facilitated, one being centralized and the other decentralized.

In a decentralized system, the trader has full power to sell or buy his asset to any person whenever he wants and thus can use his coin without revealing his identity without anyone's permission.

Thus the need now is to improve and accelerate the P2P crypto trade by adding a decentralized exchange network. In this way, the government can improve many areas of life through the blockchain system, such as tax collection and the issuance of identity cards at the national level, many benefits can be obtained by using the blockchain in the issuance of driving licenses.


Merit & Demerit Decentralization

If we talk about the benefits of decentralization system then there are many benefits of the system.

  • The biggest advantage is that in this system the transfer of power is transferred from the top to the bottom and thus every person connected to this system develops according to his ability and potential.

  • Thanks to this system, the feeling of deprivation disappears.

  • Corruption and fraud can be eliminated through a decentralized system because everything in this system can be kept transparent.

  • Under this system, money transactions can be done efficiently and in a timely manner all over the world.

  • The exchange of information between different countries in every field can be made possible.

  • The use of this system in various sectors at the government level, transparency in the use of funds can be checked to see how much funds have been spent in which sector and where.

  • Data in a decentralized system is protected from hackers and data stored in a decentralized blockchain cannot be customized by anyone.

  • In a decentralized system, traders can trade at will and transact with their money whenever they want.

  • In this system, the center authority has no role, but everyone works independently.

  • In this system, the user has full freedom of expression and everyone can make their own decisions.

In this way, this system leads the members of the society towards freedom and autonomy in all respects. But along with these benefits, there are also some flaws in the system.

The biggest demerit of system is the misuse of funds because under this system everyone is independent and they can transfer their money to whomever they want. Thus many people can use this system to commit money crime.

In addition, launching this system requires a lot of money and skilled people at a high cost. If money is transferred from an individual to a wrong account by mistake, it is impossible to get the money back, so this system requires trained people.

In addition, not everyone has the ability to make timely decisions, which can lead to many people suffering the consequences of wrong decisions. Purpose Every system has some advantages and disadvantages but since the advantages of a decentralized system are many and this system can be improved in many areas.

Block explorer

Dear students, we have read about what a blockchain is and how it works. In this way, we have tried to understand briefly about Decentralized. We will now read briefly about Block explore in simple terms . This means that the information contained in a block can also be explore to see where and by what means the information has been transferred within a block.


Block explore is a program or application in which all crypto transaction information about a particular wallet can be explored. And anyone can see how much money was received in which crypto wallet and from which account and what is the current balance of the corresponding coin in that wallet. In addition, we can explore all the information related to the transaction in block explore.

What information can we explore through block explorer?

We can explore the following information about any cryptocurrency through the relevant block explorer. When and in what time was the transaction confirmed?

In addition, how many coin were in the respective wallet before the relevant coin transaction and what is the transaction balance after.

Thus, the total amount received and the total number of coins were transferred to the wallet when and where and information about the hash tag and final balance is recorded. And all this information is called a summary of any wallet that we can see through the block explorer tool.

This way we can explore the transaction details of each coin through block explorer. Suppose you want to check the summary of Bitcoin then you have to give the address of bitcoin about which address you want to check the information. This way, if you want to check the transaction of tron coin, you can check the summary of tron accounts through tron block explorer tool.

A list of famous Bitcoin block explorers

The following are some of the most popular bitcoin block explorer tools and are very easy to use.

Tron block explorer tools

Doge coin block explorer tools

Steemit coin block explorer tools

How to use these block explorer tool to check the any Cryptocurrency coin?

How to use these block explorer tool to check the any Cryptocurrency coin?

Now we will learn the practical how to explore any crypto coin using block explorer tool. I will first explore my steemit on steemit block explorer my steemit address @Yousafharoonkhan

Above I have given a list of the three most used steemit block exlporer. You have to open one or three of them alternately to check whether the information contained in them matches the account address provided by you. Because when you explore your account, you can better read block explorer. So let's go and learn how to use steemit block explorer.

Step 1 :

First of all, you have to find the block explorer tool of the coin which has the relevant coin address. For example, if you want to search for steemit block explorer tool, you can type steemit block explorer tool in google and you will see the result of all the tools. You can open any tool.

Step 2:

Now when all the results come up, click on any block explorer tool. I am clicking on the second result which is steemblockexplorer.

When you open this tool you will have access to various information. The most important of which are as follows.

  • STEEM price (According to lattest market value)
  • SBD price (According to lattest market value)
  • Base feed price (According to lattest market value)
  • Internal market

Step 3


At the top of the tool, type steemit address in the search box to check the details. I am writing my username Yousafharoonkhan. If you do not have a steemit username, you can enter the address of the steemit that you have. This address can also be that of an exchange. They can also use. All you have to do is type in the relevant address in the search bar and all the details will be explored in front of you as I have explained in the screenshot.

Step 4

When you click on the search button, you will see all the account details. And you can see all the details of lattest transaction and balance, total voting power, downvote power, RCs of this relevant steemit account. If you look closely, you will see the details of lattest upvote in the transaction. If you want to see the details then click on the hash tag of the transaction which is on the right side with the transaction time. You can easily recognize the hash tag with the help of the screenshot given below. i want Explain here that this is the same hash tag that separates each block in the blockchain. It is impossible to change it.

this is Hash code of lattest transaction voted :

copy the code : c949f92f3e50a380e0ea92b677e3a7831cc7d436

Step 5

  • Open this steemit block explore tool steemscan

and paste the hash code or steemit address in search bar. , it is way the method to explore the any steemit account transaction detial through steemit block explorer tool. so all block explorer tool work same way.


Homework Task-2

(1) Write the definition of blockchain. And how our data on Blockchain is protected from hackers. ? And write details about Data, Hash and Previous Hash tag and explain through screenshot.


(2) Define decentralization. Describe the advantages and disadvantages of a decentralized system. In what areas of life can a decentralized blockchain be helpful? (write in own words)


(3) What is a block explorer? And what is its purpose and use? Search for different cryptocurrency block explorers and list them below. At least five different crypyo currencies. Also explore the transaction of a crypto coin on block explorer and explain with the help of screenshot.


(1) Your article should be at least 300 words.
(2) This homework task does not have an expiry, however, you can submit your assignment only once.
(3) Eligibility Criteria--

  • Must have a reputation of 50 or above
  • Must have at least 125 SP (excluding any SP delegated-in)

(4) Add tag #academy-intro02 #cryptoacademy in your post and should be among the first five tags. And also make sure you post in the Steemit Crypto Academy community.
(5) You can attempt any one out of the three questions, but you must write the entire Question in Bold letter at the beginning of the post.


Use copyright-free images or indicate the original source

Thank you.




Hi.Life is worth 1 BITCOIN.Help as much as you can, any money will be help - BITCOIN address in LEGACY format 1BXqMGyek1hCxoaTyHmkQEcbLbkSJP2duE BITCOIN address in SegWit format bc1qts5efd872etyw7mgw0t0v3lwtw032dj4jgp5t7 Thank you all in advance!

 3 months ago 

I feel u sent ur link to me directly. Pls go to the end of the lecture, ul see the reply button. Click on it and tag the professor,then add ur link so he can see it properly

oh. Sorry for that. Thanks

I so much love the insights in this article
What a great deal of research you perfomed
Thank you so much professor @yousafharoonkhan

hello professor. Welcome back to all of us in this academy once again.

Here is my assignment link

Greetings sir
Here is the link to my entry post

This is nice

AOA respected @yousafharoonkhan. What is last date of submission for this homework.

 3 months ago 

This is a fixed course and it doesn't have an expiry date. But a user is only allowed to submit an assignment once. The dynamic courses with expiry dates will kickoff next week.
Thank you.

 3 months ago (edited)

Hello professor @yousafharoonkhan
This is My Entry Post to Homework Task 2. Thank you so much for giving us knowledge.

I don't know should i post the link of my entry here or not because it is my first post here but as everyone is posting so here is my homework post ,😇..

I am eligible or not?

 3 months ago (edited)

Hello Prof. @yousafharoonkhan

Here is my home work link

 3 months ago 

Explicit post sir...will be sure to participate

 3 months ago 

Wow. What a great Lecture.


 3 months ago 

Here is my homework submission Professor @yousafharoonkhan.

Thank you.

 3 months ago 

Saludos amigos aqui les dejo mi Tarea 2

Publicado en Twitter


 3 months ago 

Hola profesor @yousafharoonkhan, termine con publicación de tarea para su clase, no se si corresponde ponerlo aquí pero como tiene 2 días dee publicado y aún no me lo corrigen por aca le dejo el enlace, muchas gracias por la clase!


¡Buen día y saludos!

Professor, Your explanation is always good, even a beginner can easily understand it and the language you use is not bookish language anyone can easily understand it, Thank you and all the best for your next lectures.

 3 months ago 

Sir, good morning and I am very happy reading, the class was very explicit to understand. I loved it. Thank you. I just have a question that I will love you clarify me more

Also, when data is filled inside a block, a new block is created to store more information and thus when a new block is created, the hash code of the previous block is entered in the new block so that it exists in the new and previous block.

I didn't understand this part. The previous hashcode, is it stored in the new block as the data for that block or just as an address and other data can be stored
So my question is, in every block is there a hashcode for the previous block and Data that is, Block = previous hashcode +Data .
Or it's different??

Hola aquí dejo mi tarea

Curso para principiantes 3 temporada cryptoacademy publicación de tarea 2 blockchain descentralización explorador de bloques por @yousafharoonkhan

 3 months ago 

Hello, professor. Here is my entry

portada tarea 2 (1).jpg

 3 months ago 

hi professor , This is my homework post

 3 months ago 

Por aquí dejo mi participación ---> Curso Principiante Tarea 2


 3 months ago 

Well am not the one who gives marks for the work. Please talk to @reminiscene professor

 3 months ago 

Well am not the one who gives marks for the work. Please talk to @reminiscene professor

 3 months ago 

Thanks for giving us this opportunity to participate in this contest and here is what I understood in your class sir


My entry was skipped during curation
Please attend to me before it passes payout

I submitted 6days ago and I have not been verified or curated and people who submitted recently have been curated, please attend to me sir

 3 months ago (edited)

Hi Professor @yousafharoonkhan My Homework Post was not reviewed yet. Please check. Thank you

My entry was skipped during curation
Please attend to me before it passes payout

I submitted 7days ago and I have not been verified or curated and people who submitted recently have been curated, please attend to me sir @steemcurator02 @steemcurator04

Saludos profesor @Yousafharoonkhan disculpe la molestia pero mi tarea aún no ha sido evaluada y se vence el día de hoy. Me gustaría saber qué procede en caso de vencerse sin su evaluación.? Agradezco su respuesta! Saludos !
Acá dejo el link de mi participación

 3 months ago 

Greetings professor @yousafharoonkhan, could you do a homework with each question? Or could I only do one task by choosing one question?

 3 months ago 

Here is my task 2 entry @yousafharoonkhan


 3 months ago 

¡Hola Profesor @yousafharoonkhan buenos dias! Gracias por sus recomendaciones, nos sentimos muy motivados y alegres al realizar esta tarea. Por otro lado le comento que tenemos un pequeño problema, nuestra publicación se vence mañana y @steemcurador2 no ha pasado por nuestra publicación. Esperamos su pronta respuesta y ayuda, muchas gracias