What does a quick format do?

A quick format creates a new file system structure on the disk, which includes generating a new file allocation table. This process essentially resets the storage device's organization, making it ready to store files once again. However, it does not completely erase the existing data on the disk; instead, it marks the sectors as available for new data. As a result, the old data is still present on the disk but is no longer accessible through the file system until it is overwritten by new data.

This approach is significantly faster than a full format, which performs additional checks and erases the data more thoroughly. The quick format method is beneficial when speed is a priority and complete data destruction is not necessary, such as when reusing a drive that has no sensitive information.