Computer is a machine designed for manipulating data according to a list of instructions known as a program.
Computers are versatile. In fact, they are universal information-
processing machines. For example, PDA -personal
digital assistant to a supercomputer. Therefore, the same computer designs may be adapted for tasks ranging from processing company payrolls to controlling unmanned spaceflights. Due to technological advancement, modern electronic computers are exponentially more capable than those of preceding generations.
Computers take numerous physical forms. Early electronic computers were the size of a
large room, and such enormous computing facilities still exist for specialized scientific computation like supercomputers and for the transaction processing requirements of large companies, generally called mainframes. Smaller computers for individual use, called personal computers, and their portable equivalent, the laptop computer, are ubiquitous information-processing and communication tools and are perhaps what most non-experts think of as a computer. However, the most common form of computer in use today is the
embedded computer, small computers used to
control another device. Embedded computers control machines from fighter aircraft to digital cameras.