EOS is a blockchain platform for the development of decentralized applications (dapps), similar to Ethereum in function. It makes dapp development easy by providing an operating-system-like set of services and functions that dapps can make use of.
The idea behind EOS is to bring together the best features and promises of the various smart contract technologies out there (e.g. security of Bitcoin, computing support of Ethereum) in one simple to use, massively scalable dapplication platform for the everyday user to empower the impending blockchain economy.
EOS promises to be a real contender in the dapp arena, lowering the barrier to entry for developer and others seeking blockchain-powered solutions.