Many websites contain so-called counters. Typically, they display the number of times a page has been accessed, or the number of times a file has been downloaded. Such capabilities cannot be implemented simply by using HTML since Counter information has to stored on the server. Therefore a program must be written to run on the server to increment the counter that you wish to display on your web page. To increment a counter you must call an URL that looks something like this :-
/cgi-bin/counters/counter.pl?name=geewhizz
Let's look at this URL a Little more closely. It calls a program called counter.pl located in the /cgi-bin/counters directory of your website. When the program counter.pl runs, it is able read the values following the ? character. It therefore knows to use a file named geewhizz, read the counter data from it, increment that data and save it back in the same file. However, in addition to incrementing a data value, counter.pl will usually also output some text - the value of the counter. This text is what you want to display on your web page.
