A birth certificate is a record of an individual's birth. It can include some valuable information such as a person's full name (if not previously known) along with the names of the child's parents.
United States Birth Certificates
In the United States, a birth certificate can be obtained either through the state's vital records office or the health department for the county where the person was born. However, the range of dates from which a state or county keeps or records birth certificates vary. For example, in the state of Alabama birth certificates were not kept on file until the year 1908 whereas Henry county Indiana keeps birth records on file from the year 1882 and onwards.
Oftentimes a county or state will offer a birth certificate in two forms: a genealogical copy or certified copy.
Genealogical copies are usually just computer printouts with most of the information that a certified copy contains, such as the person's day of birth, names of their parents, the doctor who delivered them and the county within which they were born. These can usually be obtained for a small fee, usually no more than a couple of dollars.
A certified birth certificate is an official record of a person's birth. This is usually printed up on official, watermarked paper that a government office uses for legal purposes. It will often contain the imprinted seal of the governing body. These are most often exact copies of the original record that is on file, sometimes they are computer printouts of the same information on certified legal paper. A certified birth certificate's fee for a copy can vary from state to state. The range can be anywhere from a few dollars up to twenty. Also, most governing institutions require some form of official proof of identification of the requester for this type of certificate. Some states require a copy of a driver's license or photo ID to obtain a legal copy of a birth certificate.
A reason as to why a certified copy would be desirable over a genealogical copy of a birth certificate would be if someone needed a legal document to prove their ancestry in a court or legal proceeding of some type. This can be a tool for when an inheritance needs to be distributed and legal proof of parentage would be needed.
Special Note on Birth Certificates
Bear in mind that sometimes names can be misspelled on a birth certificate. For example, you could receive a birth certificate on an individual whose father's name was spelled 'Lewis', where you will have a death certificate and an obituary on the same individual that has the father's name spelled as 'Louis'. It is a good idea to have more than one primary source to cross reference individual's names.