CCNA is the acronym for the Cisco Certified Network Associate certification from Cisco. In speech and in writing, this certification is properly referred to by the initials CCNA rather than the full name.
CCNA certification is a second-level Cisco Career certification that indicates a foundation in apprentice knowledge of networking. CCNA certification validates the ability to install, configure, operate, and troubleshoot medium-size routed and switched networks, including implementation and verification of connections to remote sites in a WAN.
To become a CCNA, a passing score on the 640-802 exam must be achieved, or combined passing scores on both the ICND1 640-822 and ICND2 640-816 exams. Passing the ICND1 grants you the Cisco Certified Entry Networking Technician (CCENT). Passing scores are set by using statistical analysis and are subject to change. At the completion of the exam, candidates receive a score report along with a score breakout by exam section and the passing score for the given exam. Cisco does not publish exam passing scores because exam questions and passing scores are subject to change without notice.
Article Source : http://en.wikipedia.org/wiki/CCNA