Origins, processing information almost exclusively related to arithmetical problems, but modern computers are used for many tasks unrelated to mathematics.
In such a definition have a tool like a slide rule, mechanical calculator types ranging from abacus and so on, until all contemporary electronic computers. The term better suited to a broad sense such as "computer" is "that process information" or "information processing systems."
Not with standing the foregoing, the above definition includes many special tools that could only take one or several functions.
When considering modern computers, their most important characteristics that distinguish them from the earlier count tool is that, with proper programming, all computers can emulate any nature (although perhaps limited by storage capacity and speed are different), and, indeed believed that the machine can now mimic the computing tools that we create in the future (although undoubtedly slower). In a sense, the limit of this ability is a useful test because the computer recognizes the "general intent" of the special purpose tool is earlier. The definition of "public purpose" can be formulated into a condition that a machine should be able to emulate a universal Turing machine. The machine that got this definition is known as a Turing-complete, and that they first appeared in 1940 in the middle of development throughout the world.