Today’s personal computers are drastically different from the massive, hulking machines that emerged out of World War II–and the difference isn’t only in their size. By the 1970s, technology had evolved to the point that individuals–mostly hobbyists and electronics buffs–could purchase unassembled PCs or “microcomputers” and program them for fun, but these early PCs could not perform many of the useful tasks that today’s computers can. Users could do mathematical calculations and play simple games, but most of the machines’ appeal lay in their novelty. Today, hundreds of companies sell personal computers, accessories and sophisticated software and games, and PCs are used for a wide range of functions from basic word processing to editing photos to managing budgets. At home and at work, we use our PCs to do almost everything. It is nearly impossible to imagine modern life without them.