Laminator pouches come in different thicknesses and different finishes. It is measured in microns and you can feel the difference both before and after the pouch has been through the lamination machine.
Thinnest/lightest being 100 micron or less if available and the thickes being 250 micron or above. Most common thicknesses are 150micron and 250micron.
The heavier 250 micron pouch is more stronger and more rigid after the lamination process than the 150micron pouch. Therefore it is more durable. The 150 micron has some firmness but is much more flexible. It is also less heavier.

The laminator itself can be any laminating device; but the pouch part comes from the laminate being a pocket or pouch with at least one side joined beforehand.
A card or sheet of paper is placed inside the pouch and then this is run through the laminator.