Use:

To find:

Mary Smith

Files containing the words "Mary" and "Smith"
The words probably will not be together

Choose Boolean from "Match" drop-down, then enter Mary Smith -or- Choose Any from "Match" drop-down, then enter Mary or Smith

Files that contain either "Mary" or "Smith" or both

Choose Boolean from "Match" drop-down, then enter (Mary or Polly) Smith

Files that contain "Smith" and either "Mary" or "Polly" or both "Mary" and "Polly"

Choose Boolean from "Match" drop-down, then enter Mary and Smith andnot Tennessee (Notice that andnot is one word)

Files that contain either "Mary" or "Smith" or both and does not include the word Tennessee