"Public and private laws are also known as slip laws. A slip law is an official publication of the law and is competent evidence admissible in all state and Federal courts and tribunals of the United States. Public laws affect society as a whole, while private laws affect an individual, family, or small group. After the President signs a bill into law, it is delivered to the Office of the Federal Register (OFR), National Archives and Records Administration (NARA) where it is assigned a law number, legal statutory citation (public laws only), and prepared for publication as a slip law. Private laws receive their legal statutory citations when they are published in the United States Statutes at Large."
"Session laws" refer to the publication of laws enacted during a legislative session into a chronological sequence. This is the function of the United States Statutes at Large.
New statutes must be added to or fit into the existing United States Code (U.S.C.). The U.S.C. contains the general and permanent laws of the United States, organized into titles based on subject matter. A complete new edition of the Code (“main edition”) is printed by the Government Publishing Office (“GPO”) every six years, and five annual cumulative supplements (designated as Supplements I through V) are printed in intervening years. The U.S.C. currently consists of 54 titles (Title 53 is Reserved) and five appendices. The U.S.C. is prepared and published by the Office of the Law Revision Counsel (“OLRC”) of the U.S. House of Representatives pursuant to 2 U.S.C. § 285b.
Because the United States Code contains only the general and permanent laws of the United States, not every provision contained in those public laws goes into the Code. The OLRC reviews every provision of every public law to determine whether it should go into the Code, and, if so, where. This process is known as U.S. Code classification.