A personal computer is a compact computer that you can use in your home. Many years ago (around 40 years) computers were enormous, they occupied maybe several rooms that required special airconditioning and dust free environments to keep them working. To operate them requires a team of people. They were hugely expensive and only owned by large companies and government organisation. These type of computers called main frame computers are still made for Government bodies for very special uses. But the personal computer or PC can be used for virtually everything at a much cheaper cost and small size. Hope this helps. Difficult one that.