It is a general-purpose tool, built around a microprocessor. A PC has many different parts such as memories, a hard disk, a modem, etc that work together. A PC is said to be "general purpose" because you can do many different things with it like: you can use it to type documents, send e-mail, browse Web and play games.

Let us look at main components of a typical desktop computer.

Central processing unit (CPU): The microprocessor "brain" of computer system is referred to as central processing unit. The CPU oversees everything that a computer does.

Memory: This fast storage area is for storing data and is connected directly to microprocessor. That's why it is fast. There are various types of memory in a computer system:

Random-access memory (RAM): Used to temporarily store information that computer is currently working with.

Read-only memory (ROM): It refers to computer memory chips, containing permanent or semi-permanent data that does not change.

To start with, what exactly is AI? http://www.dictionary.com defines it as follows: 1. The ability of a computer or other machine to perform those activities that are normally thought to require intelligence. 2. The branch of computer science concerned with development of machines having this ability. If you take a look at this you may notice that field of AI is actually far broader than many people give it credit for. Even Google search engine can be said to incorporate some of research done in AI. The definition of AI and intelligence itself sometimes varies but it's probably safe to say that a simple explanation is that if a machine exhibits a measure of intelligence in some area it can be called AI. The AI of movies is usually entirely self aware, emotive, and for all intents and purposes 'alive'. It is capable of learning, reasoning, explaining and deceiving. The AI I've experienced (and this is very basic, scratching only surface of depth of studies into AI) is far more specialized, focusing on just one aspect of a problem that could potentially be much larger. There are various areas of research being carried out into creating humanoid machines of science fiction, but as yet most are still restricted to realms of imagination. One very impressive piece of technology is Honda ASIMO project. This project has created a humanoid robot with some remarkable features. I'm not entirely sure if there's really a practical use for this (I think they're just trying to justify their funding with applications mentioned on website) but it scores points for being one of coolest uses of technology I've ever seen. You can see some videos of ASIMO in action here: http://world.honda.com/HDTV/ASIMO/