What is the importnce of file handling?

Most applications cannot operate efficiently (or sometimes even at all) without some method to save and load data of some sort. While a database may suffice in many cases, in others it's impractical (either because availability of a DBMS isn't guaranteed, the data stored isn't enough to justify the added overhead, etc.) In such cases, using a file of some sort is often the only other reasonable option. Doing so requires file handling commands to open and close the file, read from and write to the file, etc.