Affidavits can be used for many different reasons, but they all share a common trait: the person singing is making a declaration, under oath, that what is in the affidavit is true.
Affidavit of Birth. In the event you ca not locate your birth certificate, this affidavit can be used to verify some of the facts surrounding your birth. Typically, this affidavit form will be completed by one of your blood relatives or the attendant midwife or physician. This person will state their relationship to you, how they have knowledge of your birth circumstances, and attest to the pertinent information (such as county and date of birth).
Affidavit of Name Change. If you go by a name different than your birth name but have not gotten around to officially changing it through the court, use an affidavit of name change. Typically, another person (most often your spouse or a blood relative) will sign this and swear that you use a name different from your what is on your birth certificate.
Affidavit of Death. This is a fairly straightforward affidavit, usually handled by an estate administrator. It is used to notify creditors, the court, and businesses that someone has passed away. This allows the executor or estate administrator to do his or her duty in regards to the deceased s estate.