quite simply, it will cool it.
you see, laptops are all the same parts as a desktop tower, compacted down into a portable form. and even desktops have cooling fans. but with that much hardware close together, the heat grows faster.
so if the bottom of your laptop ever feels REALLY warm, get a cooling pad, and it will cool things down!
ALSO, you should NEVER set a laptop on a non-flat surface, such as carpet, couch or bed, as the exhaust vents get blocked. but with a cooling pad, it’s okay :)