A computer is a device capable of automating vast amounts of mathematical computation to solve all kinds of problems, both mathematical and non-mathematical. While early computers from the 1930s and 1940s generally were used for numerical computations such as data encryption/decryption and weather simulations, over the next sixty or so years computer technology (helped along by the invention of the transistor at Bell Labs) would advance to the point where computers could be used to enhance or enable activities such as text processing, games, and pr0n. Today's computer is often small enough to fit in a small space on someone's desk (or even in their pocket, in the form of a PDA or a smartphone), and is capable of downloading and viewing a whole lot of
porn useful information in a very short time.
A very small computer optimized for interactive use is called a calculator, and is a great way to give a math educator fits trying to figure out what to do with it.
 Things computers cannot do
- A computer cannot hold an intelligent conversation with a human being (see Turing test). It can, however, malfunction and lock the pod bay doors shut, so you might have an issue with that.
- Some computers have been able to reach the point where they can confuse, for some limited period of time, a few horny cybersex addicts on IRC and creationists.
- A computer cannot successfully upload viruses to alien operating systems. (At least not without the right network card and protocol stack. Good thing the wireheads at Area 51 are Mac users.)
- A computer cannot spontaneously become self aware, take over every computer in the world, launch a massive nuclear attack to wipe out humanity, then send artificially intelligent killer androids back in time to prevent someone from stopping it. Under the right circumstances, however, it can assume total control of the state of Caulyforneeya.
- A computer cannot do anything at all without being told what to do — and the task of telling a computer what to do is so complex that there are scientists and megacorporations that make most of their living researching better ways to do it.