Generate New Table

i have noticed that Generate Near table tool calculates the distance of input feature table with the selected feature of near feature table. this mean if in the attribute table of near feature i do nt select any record the Generate Near Table does not calculate any thing and return no records. however if i select any record in the near feature attribute table than the tool calculated the nearest distance with the selected record . is it way it work. I have read the help of the tool and did as it is directed in the help . any advice please.
thnx
nadeem