1. …………. are used to store data and programs.

2. ………. programs that guard your computer system against viruses or other damaging programs.

3. ………… is a utility program that locates and eliminates unnecessary fragments and rearranges files and unused disk space to optimize operations.

4. ………………. is one popular and free version of the UNIX operating system.

5. A computers ability to Notepad and Paint applications at a time is called as ——————.