meaning of "rolled up in the collar"

[Our Tort System]

Hi,

Here is a sentence that puzzles me a little:

He bought a parka with a hood that rolled up in the collar.

What precisely does the fragment in bold font mean? That the hood can be turned into the collar by rolling up?
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If it's not easy, don't do it!
That's how I got where I am.

[Mister Micawber]

Generally, the hood is rolled neatly into a cylinder and then can be pushed into a zippered pocket on the back face of the collar.
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Native English teacher at Mister Micawber's

[Our Tort System]

Hello MM,

That makes sense. Thanks a bunch!
_________________
If it's not easy, don't do it!
That's how I got where I am.