TAB is a short form for TABLATURE which is an easy way to write notes for the guitar. This notation gives the fret numbers on concerned strings. Using tabs one plays the Melody of a song
A Chord is when one plays 2 or more notes at the same time. Using Chords one plays the Harmony for a song.
Its not so that if you requested tabs, people respond with Chords. It may have happened in some cases but tabs and chords are 2 different things. Playing Chords with the rythm takes time and hence beginners always start with tabs.
Good Luck with your learning on IGT
A XAND B => A AND B but not BOTH