The Public Libraries data set aggregates individual library services and finance data to the town level.

Public libraries provide free borrowing privileges and services to their patrons and receive financial support from local tax funds. Public libraries may be municipal, which are established by and administrative units of local government, or association, which are not units of town government but receive some public funding. Some towns are served by more than one public library.

Library visits include all persons entering a library for any purpose, including persons attending meetings or activities and persons requiring no staff assistance. Circulation counts all library materials of all formats lent out for use outside the library, including renewals. Registered borrowers are all town residents to whom a library has issued membership. Reference questions counts all interactions in which library staff provide information, knowledge, or recommendations to patrons. Town tax appropriation indicates the funds allotted to the library's operation budget from the town. The Adjusted Equalized Net Grand List per Capita (AENGLC) measures town wealth based on property tax and income per capita.