Making calls through Google Voice?

[MobileDroid]

I just got a GV number and activated it on my Droid.

1.) When going through the settings for GV on the Droid: What does it mean to use Google Voice to make all calls? Does this mean to make the call and have my GV # show up on the other person's phone? If so, is the call still being made via Verizon?

2.) How does this work with texting?

Thanks!