Act is the official name for a bill that has been enrolled for presentation to the Governor. Each act is assigned a chapter number and is published in the bound volume called the Session Laws of the State of Minnesota.
This book serves as the only official record for temporary and special laws, such as laws for a specific unit of government or a law containing an appropriation. Those laws are not compiled in the Minnesota Statutes.
See also the FAQ: How do laws, statutes, and rules differ?