Question

what is an unit ?

Answer 1

What is your native language? :)

Answer 2

It's an adjective to describe "one" of some _thing_. For instance, a unit vector is a vector with length 1 in a direction. A unit circle is a circle with radius of 1.

Answer 3

uh lenght or magnitude @Kainui

Answer 4

Or it will be an arbitrary length, while the length itself does not affect the calculation process or result. For example, two unit times two unit always produces four unit squared, regardless of whether the unit is one inch, two meter, ten meter, etc...