What is Public Records?

Legal Definition
Public records are documents or pieces of information that are not considered confidential and generally pertain to the conduct of government.

For example, in California, when a couple fills out a marriage license application, they have the option of checking the box as to whether the marriage is "confidential" (Record will be closed, and not opened to public once recorded) or "public" (record will become public record once recorded). Basically, if the marriage record is public, a copy of the record can be ordered from the county in which the marriage occurred.
-- Wikipedia
Legal Definition
a register of the legal transactions, proceeding, rules and statutes, laws and regulations that is kept on file to be able to be referred to if needed.
Legal Definition
A record, memorial of some act or transaction, written evidence of something done, or document, considered as either concerning or interesting the public, affording notice or information to the public, or open to public inspection. See Keefe v. Donnell, 92 Me. 151, 42 Atl. 345; Colnon v. Orr, 71 Cal. 43, 11 Pac. 814.
-- Black's Law Dictionary
Legal Definition
A record required by law to be kept, or necessary to be kept in the discharge of a duty imposed by law, or directed by law to serve as a memorial and evidence of something written, said, or done. See 175 Ind. 132, Ann. Cas. 1913B, 1271, 93 N. E. 666.
-- Ballentine's Law Dictionary