Some questions from new GURPS player

[imaytag]

So, my friend is starting up a GURPS campaign and I've got some things I need clarification on.

Mainly, what exactly is an attack, maneuver or technique. Like, is a technique an attack? Mainly I want help understanding how these things work together.

For example, say I successfully defend, then on my turn decide to use a counterattack. Could I: All-out attack (Double), feint for my first attack and rapid strike the second attack into a sweep and a deceptive disarm? If so does the counterattack modifiers apply throughout the whole thing?

Or maybe I dodge an arrow, could I use move and attack to go up to him and then use counterattack?

I appreciate any help you guys can provide.

Tuck