Back-end/Server-side Programmer:
Usually uses one of the following: Python, Ruby, PHP, Java or .Net. Has database knowledge. Possibly has some sysadmin knowledge.

Front-end/Client-side Programmer: HTML, CSS, JavaScript. Possibly has design skill.

Mobile Programmer: Objective-C or Java (for Android). HTML/CSS for mobile websites. Potentially has server-side knowledge.

3D Programmer/Game Programmer: C/C++, OpenGL, Animation. Possibly has good artistic skill. C# for unity 3D.

High-Performance Programmer: C/C++, Java. May have background in mathematics or quantitative analysis