There are other meanings of this term, see Ethereum (values).
Ethereum (etherium     , from English ether [iːθə] - "ether") - a platform for creating decentralized online services based on the blockbuster (Đapps, Decentralized applications, decentralized applications ), working on the basis of smart contracts. Implemented as a single decentralized virtual machine. Was proposed by the founder of Bitcoin Magazine by Vitalik Buterin in late 2013, the network was launched on July 30, 2015.
Being an open source platform, Ethereum greatly simplifies the implementation of blocking technology , which explains the interest not only of new startups , but also of the largest software developers such as Microsoft , IBM. VTB banks  and Sberbank     , Lufthansa  and S7 , as well as the international charity organization UNISEF  showed interest in the platform.
Exchange units Ethereum are called ether (English ether). For the designation, the abbreviation ETH and the symbol in the form of the Greek letter Xi Ξ  are used. Fractional parts have their names: 1/1000 - finney, 1/106 - szabo, 1/1018 - wei.
Unlike other crypto-currencies, the authors do not limit the role of the aether in payments, but offer it, for example, as a means for exchanging resources or registering transactions with assets through smart contracts, in particular, the authors called the air "cryptoprim" for the performance of smart contracts by a peer-to-peer network [ 20]. The ether is actively traded on the services for the exchange of crypto currency. Its total capitalization in January 2018 exceeded $ 100 billion , but by August 2018 capitalization had dropped to $ 30 billion.
Ethereum technology makes it possible to register any transactions with any assets on the basis of a distributed base of contracts such as block, without resorting to traditional legal procedures. This possibility is competitive with respect to the existing transaction registration system . According to The Economist magazine, the technology of "smart contracts" marks a new era in financial technologies .
Block technologies can be successfully combined with remote banking services provided through SMS messages. Due to its cheapness, this opportunity is especially attractive for developing countries, says The Economist .
Clever contracts in Ethereum are presented in the form of classes that can be implemented in various languages, including visual programming  and compiled into the bytecode for the Ethereum Virtual Machine (EVM) before sending it to the block. The change in the state of the virtual machine can be recorded in a full Turing scripting language.
Unlike the scripting language in the bitcoin protocol, EVM supports loops, so the platform uses a mechanism called gas to limit contracts that can take a long time to complete.