I checked the website and found that its gives support for ERC 721 tokens. I know a bit about ERC 20, what is the difference between those two?
why Xcrypt gives much importance to ERC 721 too?
These are contract INTERFACES. ERC-20 token means that the token contract responds to a common set of commands. It means that the token can be transferred, requested, approved, etc in the same way as any other ERC-20 tokens.
ERC-721 is a more advanced token that is non-fungible. Think of ERC-20 as the token type for things that are money and ERC-721 as the token type for collectibles and In ERC-721, each token is completely unique and non-interchangeable with other tokens.
Exactly the difference is that ERC-20 follows the common set of commands, while ERC-721 follows unique commands differs from each other.