Bitcoin is the world’s first fully-functional cryptocurrency that is truly decentralized, open-source and censorship-resistant. It was invented by Satoshi Nakamoto in 2008-2009 as a peer-to-peer electronic cash system to give the world an alternative to the traditional banking system. It is created by a process called mining and is held on Bitcoin’s blockchain. Also, unlike traditional money, you can send Bitcoin money to anyone and anywhere without seeking permission from banks or governments.
On the other hand, Ethereum is not just a blockchain for transacting money. It is an open source platform with the mission to build, inspire and fuel next-generation decentralized applications. The applications being built on the Ethereum network would have no middle men. Users are able to interact safely with social and financial systems to transact peer to peer, therefore opening a new realm of opportunity within decentralized development on specifically the exchange of value.
So we may say that, Bitcoin can be defined as a digital money & Ethereum is a decentralized platform for programming a digital money.