Component's transform

well, you use the dots to "step through" the hierarchy of components. There is only one transform, but depending on where you start you may have to take a different path to reach it.For example:

var myGameObject: GameObject; //this var represents a GameObject

myGameObject.transform ... to access transform

myGameObject.transform.position.y ... the y component, of the position component, of the transform

var myOtherObject : Rigidbody; ... // references the game object via it's Rigidbody

myOtherObject.gameObject.transform ... // takes an extra step

each step through the hierarchy must be accounted for, so

myOtherObject.transform

wouldn't do it

but you wouldn't see the examples you suggested:

animation.transform renderer.transform

because these are two unrelated components, you don't need to step through animation to reach transform, and since "animation" does not have a component called "transform", this would not work

Rather, I might say something like :

myGameObject.renderer.enabled = true;

or

myOtherObject.gameObject.animation.Play();

note: lower-case keywords like those above (renderer, gameObject, animation, transform) are a keyword shortcut to the corresponding component on the object containing the script, for example:

transform references the Transform component on this object,

etc