Frozen card:

You can freeze and reactivate it at any time for any reason you choose. Once the card is frozen, you will not be able to use it until you reactivate it.

Blocked card:

This action is irreversible. If you choose to block the card, it will no longer be usable at all. You should destroy it if you still have it.

If there are any pending transactions at the time of blocking, they will not be affected.