The swirl in the bottom half of the clef cirlces around the G line of the clef. It also looks a bit like a G.

Treble clef, because it indicates the position for G.

Yes, the treble clef can also be known as the G clef, as the line that the circle of the clef is on, (the line second up from the bottom) is where the note of G is written.

the treble clef :)

G clef is another name for the treble clef (it circles the G line on the staff). It represents a higher range than the bass clef.