Thrust reduction is reducing the thrust from take off thrust to climb thrust. Generally happens between 1,000 to 1,500' agl depending on airline SOP.
The acceleration is increasing your speed from V2+10 to 20 (roughly 150-160 knots for most medium jets) to your initial climb speed, generally 250 knots. As you pass through the various bugged speeds for flap retraction you clean up the aircraft as well.
In order to actually increase the speed the aircraft has to be pitched down, slightly reducing the rate of climb but otherwise there would be no way of accelerating. In the A320 this is from 15-17 degrees nose up on the initial take off down to about 10 degrees nose up.