Bricks, Masonry, Asphalt and Concrete - Driveway Cracks Repair

My concrete driveway is around 4 years old. Last year some long hairline cracks appeared and after this winter the cracks have widened (now around 1/4" to 3/8" wide at the surface with small pieces of the concrete around the cracks having broken off. I have been told that this can easily be repaired by myself using a concrete sealer from somewhere like Home Depot. Is this advise sound or are there better methods? I have looked around Home depot and can only find bags of concrete and not concrete sealer - where would I get concrete sealer from?

Thanks

Sealer will not help. It is liquid and will just flow down through the crack and into the base underneath. Perhaps they told you concrete "sealant", as in a caulk-like substance. There are products sold at HD, Lowes, etc. that are crack fillers, but do not apply them expecting them to match color-wise. They are probably your best bet.
Bagged concrete mix will work temporarily, but will chip out of the cracks when the concrete expands/contracts/moves with the seasons. It also will likely not match color-wise.

Pecos

Thanks for the very useful info Pecos. Not sure what I'll do yet but grateful for the clarification.