Each and every computer softwares/applications need to store and retrieve the required information.
But the problem is that when the process is running one the computer system, the application can store only some limited amount of information in its own address space.
Here, the capacity of the storage is restricted to the virtual address space's size.
Another big problem is that when the process terminates, the information is lost. And for many computer applications, the stored information must be retained for some time or forever.
Another big problem is that it is necessary for multiple processes to access the information at the same instance of time. Let's consider an example, if we have an online telephone directory that are stored inside the address space of a single process, and only that process can access it.
Therefore, to solve this type of big problem is to make the information itself independent of any one process.
After facing the above big-big problems, now to short out these problems, we have the following three essential requirements for the long-term storage of essential information that are stored through computer applications:
|1||It must be possible to store a large amount of data.|
|2||The information must survive the termination of the process using it.|
|3||Multiple processes must be able to access the information at the same time.|
The solution to all the above three big problems is to store the information on disks and other external media in units called files.
You will learn all about files in operating system in detail, divided into following tutorials: