The two types of Personal Computers. A. IBM PC's and compatibles. IBM allowed others to imitate its machine. Mac clones are rare. Until recently, the main difference between PC's and Mac's had to do with what is known as their user interface - that is, the way they presented information on the screen and solicited and responded to your input.
Programs are sets of instructions that tell the computer what to do and how to do it.
Spreadsheet programs are number crunches, allow you to perform almost any math calculations. Database Management programs let you store, retrieve, and manipulate large collections of information, such as mailing lists, inventories, student rosters or library card catalogs. Accounting programs help manage your money. Game, entertainment, and educational programs. What you want to do with the computer will determine which program you should use.