What is the definition or description of: laser scar removal?

No such thing! Lasers can be used to excise, resurface, or lighten scars, but scars are permanent, and no surgeon or technique presently in existence can permanently remove or eliminate scars. Of course, a bad scar can be excised and replaced by a (possibly) better one, or one with improved orientation or appearance.
Laser scar treatment. The term laser scar removal is really a marketing ploy. Laser treatment can significantly improve the appearance of scars and make them imperceptible but i would not guarantee "removal". The laser serves to soften the scar tissue, remodel the collagen, and smooth the skin. Other treatment modalities can improve the pigmentation if needed. Scar revision is cutting out the scar and resewing it.