Internet bots which are also known as "web robots" and simply just "bots" are mainly software applications that run automated tasks over the internet. These bots perform at a much faster rate than a human editor could and so therefore are very important.
A large use of bots is web "spidering", in which a script, a "spider", analyzes and caches information from web servers, and at a speed much faster than a human could.
As with all scripts on the internet, bots can be used for malicious purposes. They can be used to attack a server with spam (known as spambots) or to cheat on online video games.