The operating system also gives you and your programs a series of tools to help you manage files. Much of what the operating system does is not obvious to the user. Almost all programs interact with the operating system, but the user does not usually need to know when that is happening. Whenever you deal with the directory structure, you are dealing with the operating system, even if you are in another program. In addition to the things operating systems do for other programs, they have some special programs that help you control your system directly.