What are the differences between DAWN public-use and restricted-use data?

DAWN public-use and restricted-use data differ in terms of access, availability, and variable groups. Users can reference the Analysis Options for DAWN Public-use and Restricted-use Data page for help with determining which available option best meets their research needs: public-use (downloadable data), SDA (?) (online analysis of public-use data), or the Data Portal (?) (virtual desktop access to restricted-use microdata).