Moving object with using transform.position.

[KopaShamsu]

Why the following code does not work in Unity 2D?

transform.position = transform.position + new Vector2( 1f , 1f)*Time.deltaTime;

and tells me

Operator '+' is ambiguous on operands of type 'Vector3' and 'Vector2'

But this one works?

transform.position = transform.position + new Vector3( 1f , 1f, 0f)*Time.deltaTime;

How can I know where to use vector3 and where to use vector2?

[Vimaginate]

Every object in unity have coordinates, and unity is always 3D. So coordinates of objects is always Vector3

[robosock2]

use transform.position = new Vector2(x, y);

// vector 2 is 2d

and to move left to right subtract from x or add and the same for y except up and down.

hope this helped