Today you can get a 3th drive for . 1 tb is about 100,000 times larger. A computer is an electronic device which works within a binary digital system and has 4 main functions: Motherboard: the main circuit board of system unit. Central processing units (cpu): does all of the processing. Went from multiple cpus to a single chip that acts as multiple cpus. Each chip has different levels of cores. Measured in hertz (1 hz = 1 cycle/signal per second) Benchmark - software used to test and evaluate cpus. Overclocking - pushing it beyond rated speed. Processor / cpu: the speed at which your system runs programs, Clock speed and number of cores determine processor performance. Computer chips and cpus are made of silicon. Transistors: a semiconductor device used to amplify or switch electronic signals and electrical power. The more transistors, the faster the information can be processed.