Контрактом же его можно считать, поскольку он обеспечивает выполнение соглашений между сторонами. They're constructed on a technologies called blockchain. That is a type of ledger that documents and verifies transactions made on it. All transactions built on these so-named decentralized networks are community and never managed by one governing entity. https://ethereum69123.blogoscience.com/38401891/what-does-сеть-эфира-mean