What does desiredVelocity do?

Hi,
What does desiredVelocity do? What's diffrence between velocity ? And why should i use it ?

Example Code:

Code (CSharp):

1. oid NavAnimationUpdate()
2.     {
3.  
4.         speed = Vector3.Project(agent.desiredVelocity, transform.forward).magnitude;
5.  
6.         // angle is the angle between forward and the desired velocity.
7.         angle = FindAngle(transform.forward, agent.desiredVelocity, transform.up);
8.  
9.         // If the angle is within the deadZone
10.         // set the direction to be along the desired direction and set the angle to be zero.
11.         if (Mathf.Abs(angle) < deadZone)
12.         {
13.             transform.LookAt(transform.position + agent.desiredVelocity);
14.             angle = 0f;
15.         }
16.  
17.         animSetup.Setup(speed, angle);
18.     }
19.  

 

DesiredMoney = How much money do you want in your bank account?
Money = How much money you actually have in your bank account.

Same concept.
Desired Velocity = "The speed I WANT to go." (Max Speed)
Velocity = "The speed I am actually going". (Current Speed)

 

@Cynikal Thank you so much