Solana, like Ethereum, supports other tokens as well as native SOL. SPL is the token standard for Solana network tokens, analogous to ERC-20 tokens on the Ethereum network.
Note: When depositing SPL tokens, please send tokens to the Solana wallet address and not the derived SPL token address.
A list of SPL tokens that are supported on Gemini for custody can be found here, and a list of SPL tokens supported for trading can be found here.