Ethereum Competitors

Having recently fell into the rabbit hole that is Crypto my mind is blown at seeing the potential of Ethereum. Specifically smart contracts, this concept truly has the potential to change the world. NFT's really look like they can explode once gas fees are reduced and mass adoption begins.

​

My question is who are some of Ethereum's competitors? Do other blockchains use smart contracts? If not, do they offer the ability to have NFT's through different avenues? I can't imagine Ethereum being the only one to offer the capability of having unique data you can own on the blockchain.