The TIGER files include boundaries for all of the geographic areas that the Census Bureau publishes data for, as well as features that are used to delineate those boundaries (roads, railroads, rivers, bodies of water, major landmarks). Files are published in a shapefile format in for use in GIS software and are updated annually as legal areas change (counties, cities and towns). Statistical areas (block groups, tracts, ZCTAs) are only updated every ten years in conjunction with the decennial census (with exceptions for refinements to correct errors or to accommodate changes in legal areas). Tabular census data can be joined to the appropriate shapefile using the unique GEOID field to create thematic maps. It's important to use boundaries that match the given decennial or ACS dataset - there is a big difference between files from 2019 and 2020.
See the GIS Research Guide for information about GIS services at Brown.