spl mints vs token accounts

on solana, a mint only defines the token metadata; it doesn't hold value. tokens live in token accounts (tas) which link an owner to a mint. most users rely on associated token accounts (atas)—deterministic pdas derived from the wallet and mint—ensuring every user has exactly one standard account per token. minting requires the mint authority, while transfers need the owner's signature on the source ta. unlike ethereum's contract-mapped balances, solana accounts are distinct storage slots. closing a ta returns rent to the destination, but this operation fails unless the token balance is strictly zero.