NFTs are one of a kind digital objects created and stored on the Ethereum blockchain, a technology which can be thought of as a giant global computer created and powered by individuals all around the world. Blockchain is the technology that powers cryptocurrencies like Bitcoin (and is often an overused buzzword).
NFTs are similar to cryptocurrencies, except each token is completely unique with its own “DNA”. For example, in the case of Gods Unchained, each card in the game is its own NFT, where the data which it’s made of (it’s stats, when it was created, who’s owned it, etc.) is permanently recorded on Ethereum and can be viewed by anyone.
If you’re new to this technology, don’t be discouraged if you don’t understand everything right away. What’s important to know is you don’t need to be a computer scientist or genius to benefit or make use of these innovations, you just need to learn the very basics (and I assure you, it’s easier than you think).