Many token applications need an on-chain approval before a smart contract can move tokens for a swap, deposit, or other action. The approval sets an allowance for a particular contract and token.
Allowances can remain active
A permission can be limited to a specific amount or set to a very large value. Large approvals reduce repeated transactions and fees, but increase the amount at risk if the approved contract or interface is compromised.
Disconnecting a site from a wallet only ends the current connection. It does not cancel an allowance already recorded on-chain, and permissions generally do not expire automatically.
An allowance can outlive the current session
Disconnecting a website does not necessarily change an approval stored on-chain. The spending permission remains until it is used, expires by design, or is revoked.
Review and revoke
Approval-checking tools can list allowances for an address on a selected network. Revoking sends a new transaction that changes or removes the permission and therefore normally requires a network fee.
Verify the tool and network, remove permissions you no longer need, and approve only the amount required when practical. Revoking a token allowance is different from withdrawing funds from a protocol position.
Limit the spender and amount when possible
Review which contract receives permission and whether the allowance is exact or unlimited. Smaller scopes reduce exposure if an application or spender is later compromised.
Sources
Educational information, not investment advice.