System admins are required in every office nowadays and therefore Cisco certified courses are on boom. These certifications are provided by Cisco Systems and mainly there are four or five levels in such courses. Entry level is known as CCENT in which, the professional has a basic knowledge of routing and switching and can resolve the basic issues. After entry level, comes associate level called CCNA or CCDA.
A level above associate is professional called as CCNP or CCDP, and then comes the expert level known as CCIE or CCDE. Another course is of Cisco certified architect called as CCAr. So, according to the levels of certification, the job profile and salary of any candidate is decided.