The AND, OR & Match exact phrase features...
When choosing "AND" the program looks for entries containing each keyword,
for example keywords "Free software" using "AND" would return
results of entries containing the word "Free" and the word "software".
If "OR" is used, the returned results would be entries containing
the word "Free" or the word "software". The other choice
is to select "Match exact phrase" which would return results of
entries containing the words "Free software" in that order.
