PC stands for "Personal Computer". The term was coined in the 70s for machines that are used directly by one person at a time. This was a huge paradigm shift over the big and expensive mainframe computers that were common at the time. Early examples of Personal Computers include the [[Apple II]] and the Commodore PET.
Nowadays the term PC usually refers to IBM compatible PCs. IBM built the original IBM PC in 1981 , later followed by the IBM PC/XT in 1983 and the IBM PC/AT in 1984. Since IBM decided to open up the design other manufacturers started to sell clones of the original IBM PC and it's successors, so called "IBM compatibles". This allowed the IBM PC architecture to quickly become the industry standard for Personal Computers intended for business oriented tasks.
The IBM PC is the ancestor of most modern desktop and laptop computers. In the early 80s, PCs were rather expensive and not really suited for multimedia. They were not often used as home computers. This changed throughout the 90s when better graphics and sound cards appeared, PCs became cheaper and modern operating systems made them easier to use.