What is Demand Paging?

Demand Paging is a system that allows the computer to buffer only the important programs and codes for a certain operation. In other words, whenever a user accesses a program, the computer would bring into the buffer the most important files of the respective process, so the user could take advantage of those files a lot easier.

This procedure makes sure that the computer is fast and that all the actions of the user are executed fast. Once the user changes the main working program, the Demand Paging concept brings other files into the buffering memory of the computer.

The advantage is obvious: only the important pages are used during execution, so the RAM memory saves space, while the ROM memory is only used when it is needed. Moreover, this procedure allows the users to run several processes at the same time, as long as the buffering memory of the computer allows this. One disadvantage of the process is the fact that the buffering memory might have difficulties in accessing a page for the first time, and the systems are a lot more vulnerable to exterior attacks while Demand Paging is active. Moreover, if the needed page is not accessible in the ROM memory, the program could act as faulty, and the reliability of the system could be affected.