The US Census currently distributes two zips for ZIP Code Tabulation Areas (ZCTA) data with 33,114 features,
Gazetteer ZCTA (59M)
http://www2.census.gov/geo/tiger/GENZ2016/shp/cb_2015_us_zcta510_500k.zip
TIGER ZCTA (502M)
http://www2.census.gov/geo/tiger/TIGER2015/ZCTA5/tl_2015_us_zcta510.zip
What's the difference between the Gazetteer and TIGER data? Why such a large file size difference? Which one should I use? They both have 33,144 features.
Likewise, we see that with the state dataset, Combined Statistical Areas csa, and Core Based Statisical Areas cbsa
Gazetteer State (4.6M)
http://www2.census.gov/geo/tiger/GENZ2015/shp/cb_2015_us_state_500k.zip
TIGER State (15M)
http://www2.census.gov/geo/tiger/TIGER2016/STATE/tl_2016_us_state.zip
Gazetteer CSA (2.5M)
http://www2.census.gov/geo/tiger/GENZ2015/shp/cb_2015_us_cbsa_500k.zip
TIGER CSA (18M)
http://www2.census.gov/geo/tiger/TIGER2016/CSA/tl_2016_us_csa.zip
Gazetteer CBSA (6.4M)
http://www2.census.gov/geo/tiger/GENZ2015/shp/cb_2015_us_cbsa_500k.zip
TIGER CBSA (50M)
http://www2.census.gov/geo/tiger/TIGER2016/CBSA/tl_2016_us_cbsa.zip