Mechanics, autos: what is a sill flange?

Self-tutoring about autos: the tutor mentions the idea of a sill flange.

The following is according to my understanding.

In yesterday’s post, I began with the idea of a flange. The motivation was that I was recently looking at a reference about jacking locations on a vehicle, and it mentioned points along the sill flange. I found them easily enough, but wondered what it meant.

Apparently, the sill on a vehicle runs between the front and rear wheel wells. (There is one either side.) The sill is structurally strong, because it’s where the doors attach to the vehicle. Then the sill flange is, in turn, where the sill attaches to the “outer” body of the vehicle.

It makes sense, therefore, that the sill flange might host a jacking point, being a key part of the structure of the body of the vehicle. Having looked at it from underneath, I could see two or even three sheets of metal coming together there.

Source:

moneysavingexpert.com: Where are the “sills” on a car?