Contract address is the direction used for indicating in a specific network information about a crypto currency, for example:

BTCSTBinance Smart Chain0x78650B139471520656B9E7AA7A5E9276814A38E9
TRXBinance Smart Chain0xf230b790E05390FC8295F4d3F60332c93BEd42e2

A given currency might have presence on different networks, so the contract on each one of them will be different.

Always pay real attention to the contract address, specially when adding it to your wallet to make sure you’re not stolen by fake contracts.