What is car suspension alignment?

Car suspension alignment refers to an adjustment of a vehicle's suspension – the system that connects a vehicle to its wheels. It is not an adjustment of the tires or wheels themselves. 

An off-center steering wheel can be caused by worn steering or suspension parts. Just getting an alignment won't fix the root cause.  So will repair or replacement of suspension and steering parts — struts, shocks, ball joints, tie rods, bushings, or control arms.