I have my certification through the National Certification Corporation (NCC). They specialize in Maternal-Child Nursing areas. Mine is in "High Risk Neonatal Nursing". This certification body gives us the ability to use the initials "RNC" behind our name. (eg: Jane Doe, RNC) Different certifying bodies have different initials, so you may see several different ones through the years. Also, the NCC has a special certification program for Neonatal Nurse Practitioners too.
Before being allowed to take the test, we have to have our manager fill out a paper verifying we have had at least 2 full years of recent full-time nursing in our specialty area, so it's not like something you can do as soon as you get out of school.
The test costs a lot to take and is very difficult. As a comparison, the NCLEX-RN basically tests for "minimum competency" which shows you are "safe to practice nursing". It's like having to pass the test with a C. Certification tests, on the other hand, test for "expertise" in a "specialized" area. It's like having to make an A+ on the test. At least this is how I understand it.
Our hospital reimbursed us for our test fee, travel and hotel room fees if we passed the test. We also received a $500 per year bonus once a year. Our Clinical Ladder Program included certification as a way of reaching a higher rung... leading to more money and recognition. It also looks good on a resume.
I was fortunate enough to pass my exam on the first try, but not all people are able until the second time. Some never pass and decide not to try anymore. Remember some of us simply don't test well. Anyway, it feels good when you've been a nurse for a while, to have something to do to help validate your feelings about your work and knowledge. Kind of a pat on the back. We need things in our profession to help us feel like we are continuing to grow professionally.
By the way, a person can be certified in many different areas. My sister has her certification in Pediatric Nursing (from another certifying body) as well as her High Risk Neonatal Nursing certification from NCC. Most people keep their certification current by submitting continuing education credits to the certifying body every 2-3 years and paying a fee. We can always let our certification lapse if we choose to.
In case you are interested, here is the web site:
National Cerftfication Corporation
Hope this has answered a few of your questions. Wishing you all the best in your nursing career! Sounds like you are a real go-getter and I'm expecting you to have your certification someday too.