"IT" is an odd term. It means information technology but it suggests the whole cadre of people who run the network and computers in most companies.As a career, it divides into a few categories. 

Network management - These are the people who manage the servers and networks and backups and email of most companies.

Development -This can either be developing business applications in most companies. Or, the really ambitious silicon valley type development where new technologies are applied in new ways.

Want to learn about online marketing, SEO, anchor text, search engines, PPC?