Velas Native Token is used inside Velas Network and also is needed for swapping between your accounts: Native, EVM, Legacy, and for staking.
Velas EVM Token is used inside Ethereum Network and needed when you want to swap VLX to Ethereum ERC-20, BEP-20 tokens.
Velas Legacy Token is used for interacting with old exchanges and exchanges that have not yet switched to Velas EVM or Native. Legacy Addresses (that always start with V) essentially are 20 bytes Ethereum-like addresses but encoded differently on UI. The difference is that instead of a hex string prefixed with 0x, the Legacy address is extended with checksum (4 extra bytes), encoded with Base58, and prefixed with ‘V’.