...
- Selected Detailed Tables - this allows you to choose specific data from various categories for the Census year you are downloading
- All Detailed Tables - in summary file format - this will download all tables from the Census year you are downloading - can be very data and memory intensive
Not all kinds of data are available at every geographic level. For instance, income data are not available in each Summary File. Other data are not available at the smaller geographic levels (Block level). There are times when you might have to settle for larger geographic coverage than you might want, or to get smaller sample sizes from the Census data than desirable.
Most data that is useful for GIS is available in the Summary File 1 or Summary File 3 data sets.