What does the trac control mean if its on - 2003 Chevrolet Impala

Traction control. Computer controls the traction when it sees a tire going faster than another.

It means your traction control system is off.
If you are on a wet road for example and your wheels starts to slip, what traction control does if it is on, is to electronically slow down your wheels until you regain traction on the road again.

what do i do about this

the trac light is the traction control, the abs light means the antilock brake system is not functioning properly. the trac control is no issue. the abs will not cause the brakes to fail but they will lock instead of pulsing.

It means you turned off the cars' Traction Control. The traction control tries to keep your wheels from spinning and keep you on the road. By pressing the TRAC button and turning the traction control off, the computer no long tries to keep the wheels from spinning (a good thing if you want to peel out!)

I comes on and off when ever I start the

VSC - Vehicle Stability Control ,
Trac OFF - Traction control Off

it means that the TRACtion control is turned off,(it stops the wheels spinning on loose,gravel etc.for maximum safety on road,keep it turned on...

trac on trac off (traction control system)
tyre preasure light on mean that these sensors
may have been damaged or placed out of calibration during your brake repair

trac means traction control. it is usually used when the road is wet. to gain better control