Freezing your card temporarily blocks its use, whether it's a physical or virtual card. You have the option to unfreeze it later if you wish to resume using it.
To freeze your card, you can do so via the web interface or the App:
Navigate to the Cards section in the left-side menu of the web interface. In the App, scroll down to the My Card section.
Select the card you want to freeze.
Click on Freeze.
To unfreeze, simply click on Unfreeze.