How does rigidbody velocity works?

I read the documentation, and it says:

The velocity vector of the rigidbody. It represents the rate of change of Rigidbody position.

So, there it comes this example:

if (Input.GetButtonDown("Jump"))
            rb.velocity = new Vector3(0, 10, 0);

But…I still can’t understand very well how does this works. Does the 10 means the object moves in the Y axis until its velocity reaches 10?
So yeah, I can’t honestly understand how the velocity of a rigidbody works.

Lets try to simplify things… A rigidbody’s velocity affects the “rate of change of Rigidbody position”, this means that the rigidbody’s position will be affected by the velocity in each frame, until you declare otherwise.
rb.velocity = new Vector3 (0, 10f, 0); - This means that rb’s X velocity will be 0 units per second, Y velocity will be 10 units per second, and Z velocity will be 0 units per second.

Once you set a velocity to a rigidbody, it will keep moving at that velocity until you tell it otherwise.