I am painting my second guitar. In first i painted self made body. I used acrylic lacquer(clear and Color). I didn't used any kind of sealer. Which later resulted not a perfect finish.

No in 2nd i am refinishing an old guitar. First i stripped paint which was polyurethane(Don't ask how i stripped it.) Now iam going to paint this body with acrylic lacquer.
Any way my question is that i went to a paint store and i asked for a sealer. He showed me a Primer Sealer. Is that same as sanding sealer?
I read sanding sealer is used level the gaps in wood grain that cannot be leveled by filler. And primer is used to make body body opaque and so grains cannot be through paint.

Correct me if i am wrong. Any advice will be appreciated.