[singlow]

A move closure takes copies of the environment, instead of mutating the parent environment.

https://doc.rust-lang.org/book/closures.html#move-closures

[pdpi]

It's more accurate to say that it takes ownership of the captured environment. Whether that means copying the values or moving ownership depends on whether the values are of a type that implements Copy

[rdtsc]

But isn't it confusing that it is called "move" instead of "copy" if it takes copies?

[steveklabnik]

Move and Copy are identical at the assembly level. The only difference is what you can do with the older binding. Semantically speaking, both cause a memcpy, though the optimizer may elide them.

That said, you're right that saying "copy" is misleading, for this reason. But moves _are_ a kind of copy.