1) John AND Ruffin retrieves
fgs in which the words John and Ruffin both appear somewhere in the fgs.
2) "John Ruffin" (with quotes) retrieves fgs where the word John appears next to the word Ruffin.
3) John Ruffin (without quotes) finds fgs where either the word John or the word Ruffin appears.
4) John ANDNOT Ruffin retrieves fgs that contain the word John but not the word Ruffin.
5) Richards* finds all words beginning with Richards, including Richards, Richardsen, Richardson, etc.