ABSTRACT
Most of the programs that you use on a regular basis would be far less useful if they did not have the ability to read from and write to files. Consider a word processor that could not save your files and let you load them back in later. A program where you had to print output to paper before you closed to program to have any record of what you had done. Such a program would not be very useful, and it would not be used much. That is true even if it provided you with a very full set of other capabilities.
