ZQS Software is an American multinational company that develops and markets security software for the Windows operating system.
In general cense, a lock is a mechanism that blocks unwanted access to a folder or a file. However, in computer science, the term "lock" has a more precise meaning: lock is a mechanism that prevents a file or a folder that is used in one process from being accessed, modified, or deleted from another process. In this sense, a file lock and a folder lock are distinguished.
The security software program, Folder Password Expert, uses the lock mechanism to limit access to files and folders on internal drives and to protect them from being copied, modified or deleted.
Folder Password Expert keeps a handle on all the protected files/folders on the internal drives. That is if you try to copy, move or delete a locked folder/file, you will get the "folder/file in use" message. If you want to access the locked folder, you need to enter the password and release the lock.
The lock is an important part of Folder Password Expert as it allows to protect data from being corrupted or invalidated when unauthorized users try to access the folder. When you enter the correct password, Folder Password Expert releases the lock and unprotects the folder. After that you can access your data.