Servo Terminology- Following "line" speed.

I've got the perfect project to serve as my first servo programming project. I'm in the process of gathering information and talking through my options. I'm struggling with terminology, though. Of course, there are a lot of applications where servos are use for positioning. This application is different. It gets "line speed" information from an encoder, and when a cycle starts, it uses that input to match the line speed for a short period of time. Then, the servo disengages and moves back to "home", waiting for the next cycle.

When I'm speaking with a sales engineer, what do I call that type of application? A follower??

It would help us to know what the whole application is....
But with the very little info, I would tell the sales engineer it needs to "gear in" to the master encoder

Now the next million dollar question would be does it need to "gear in absolute or "gear in relative".....?

First you don't need a servo to that, a good flux vctor drive will do that.
use the encoder as an input speed referance the trickey part is getting the Acel and Decel
correct.
Look up line shaft scynronation

It looks like a flying cutoff.