Typically, they don’t have any seal.
They just slide on the face.
If you want to make it air tight, you’ll have to add something to the door or to the wall so that when it’s shut, it seals.
Basically what we normally recommend is just a door sweep, something that goes along the bottom of a swing door and seals between the floor and the bottom of the door.
You either put those around, either the perimeter of the door, so they are attached to the door and they slide against the wall, or you can put them around the perimeter of the opening and they touch the door as the door slides across them.
Most people prefer to have them on the door because if you put them on the opening and you slide the door out of the opening, you’ll see that weather stripping around the opening, attached there.
For the most part, you’re pretty much limited to using brush weather stripping, because if you use a vinyl or a silicon weather stripping, the friction of it, sliding across your wall will wear it out prematurely.
Brush holds up a lot better against that type of use.
Since you’ll be using a brush strip, you won’t get a sound rating, and it’s not going to be a perfect seal, but it will help prevent most air infiltration and that kind of sliding door hardware.
The absolute best way to keep debris out, on an exterior door, is to build an overhang over the top of the overhang, like the roof of a porch or something.
Then put weather stripping around the door still, but that overhang is going to prevent most of the wind blown rain or snow or weeds or sliding door hardware, from getting in and around the top part of the door.