https://steemit.com/eos/@trogdor/eos-vs-ethereum-for-dummies "Not long after the launch of Bitcoin, savvy individuals began to recognize that the technology behind Bitcoin has vastly greater potential than simply as the basis for a new electronic currency. In fact, within just a few years of Bitcoin's development, dozens of new decentralized applications have been built upon the same type of public ledger blockchain technology behind Bitcoin."
examples of decentralized apps:
encrypted messaging (Bitmessage)
decentralized exchanges (Bitshares)
gambling/betting (Peerplays)
cloud computing (Golem)
social media (Steem/Steemit)
EOS was created to make it easier to build applications such as those listed above.