Difference between these 2 scripts to move an object

hi guys

been messing around moving an object

i originally worked on this one

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. public class UfoControl : MonoBehaviour
5. {
6.     public float speed;
7.     private Rigidbody2D rb;
8.     private Vector2 moveVelocity;
9.     void start ()
10.     {
11.         rb = GetComponent<Rigidbody2D>();
12.     }
13.     void update ()
14.     {
15.         Vector2 moveInput = new Vector2(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical"));
16.         moveVelocity = moveInput.normalized * speed;
17.     }
18.     void FixedUpdate ()
19.     {
20.         rb.MovePosition(rb.position + moveVelocity * Time.fixedDeltaTime);
21.     }

then worked on this one

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. public class ControlUfo : MonoBehaviour
5. {
6.  
7.     public float speed;
8.  
9.     private Rigidbody2D rb;
10.     private Vector2 moveVelocity;
11.  
12.     private float ufoSpeed;
13.  
14.     void Start ()
15.     {
16.         speed = 3;
17.     }
18.  
19.     void Update()
20.     {
21.         float axisX = Input.GetAxis("Horizontal");
22.         float axisY = Input.GetAxis("Vertical");
23.  
24.         transform.Translate(new Vector3(axisX, axisY) * Time.deltaTime * speed);
25.  
26.     }
27.  
28.     void FixedUpdate()
29.     {
30.      
31.     }
32. }

The second one is shorter,and seems to work better...the object moves smoother as well as stops much nicer when a key isnt pressed

but it doesnt seem tobe using a rigid body to move,i have never seen this.

what is the difference between the 2? will i have problems adding boundries etc etc with the second script?
sorry,complete newb here!!!

thanks for reading

 

oh i see when i coded stuff it added the rigid body portion,is that right? does unity add stuff automatically?

 

Using a Rigidbody to move an object will make it obey physics such as collisions and gravity, and also takes into account attributes like velocity and mass.

Using the Transform component to move an object does not.

 

so its obviously better to use rigid body for a player object...transform would be for like an arrow pointing the player in the right direction etc

oh and thanks for answering...appreciated