In order for a computer to do anything useful, other than act as a door stop, it must run a program. A program is simply a list of instructions that tell the computer what to do. Programs are written in languages that define the instructions that can be used and how those instructions are formatted. "C" is a powerful computer programming language that is used widely in industry. This website provides a (hopefully!) gentle introduction to the language. If you read through the pages on this site, by the end you will be able to write your own computer programs in C.
To get started, click on the link labelled "next" below. On each webpage there will be a link like this that takes you to the next page. There are also three links at the bottom of each page. The home link will return you here, the table of contents takes you to an overview page so that you can go directly to the part of the site you are interested in and the about link provides some background on the site.