A few years ago, there was a lot of IT professional who was the "do it all", aka "IT guy". Over time, this anthology has changed and brought the sectorization of professionals. We created an article also talking about 5 tips to start a career in you , I believe it can be of great help to you. With this, there was a specialization by a large part of the employees in this sector. There are people working only with databases, only with programming, only with design, others who design applications, others who test applications. But basically "does it all" is almost extinct. See also the types of information systems in companies .
I will now list the main areas of expertise, what each person should do at work, how much they earn, the pros and cons of the area.
The Database Administrator (DBA - DataBase Administrator) is responsible for maintaining and managing databases, or database systems. This professional manages, updates, monitors the information center of a system.
The network analyst or network administrator is responsible for managing the local network, as well as computational resources directly related to the network.
The profile of this professional must have a technical or higher degree in Computer Networks, Computer Science or equivalent, and / or be a person with extensive experience in the area of information technology.
Microsoft Certified Professionals (MCP) must first possess a degree in computer science, information Technology or related areas.