In order to prevent long-term invalid occupation, the Solana network charges rent for storing status information (such as accounts, smart contract status, etc.). In the Solana wallet, adding a new token will automatically deduct about 0.002039 SOL in rent, and the first transaction will deduct about 0.024 SOL. These fees are used to pay for the storage costs of the account, because the blockchain cluster must actively maintain data to process future transactions.
Each Token or NFT has a separate account, and a certain amount of SOL needs to be paid as rent when it is first obtained. If an account is no longer used, such as a remnant account of a sold NFT or a worthless token account, these accounts can be safely closed and the rent returned to the main account.