I have the impression that a "tarp tent" has bug netting permanently attached to the waterproof outer.
A tarp tent has areas where you just get bug netting, like ventilating panels around the top of the groundsheet. And there are areas where you just get solid fabric, like the roof. And there are usually inner doors made from netting and outer doors made from waterproof fabric, so you can alter the balance of ventilation/shelter/views/privacy.
A "normal" tent doesn't mix fabrics like this. It will have a waterproof outer layer, and maybe a separate inner layer of mesh (for insect protection with ventilation) or nylon (to block wind and splashes).
The "tarp tent" saves weight and space by not doubling up layers where it doesn't need to. You don't need insect netting at the roof, you need it at the doors and around the edges.
The "normal" tent may sometimes be optimised by changing components — you bring a mesh inner for insects in summer, and a solid inner to block wind and blowing snow in winter.
Henry Shires' Tarptent company, who make the Double Rainbow, make both types of tent. If you look at the setup videos on their website it will be clear which you're dealing with.