Dispatch

I'm an HVAC service tech. I'm starting a job with a manufacturer and my job's going to involve going around the country. I've never been union so I had to go down to the local today and sign paperwork. I was sponsored as a journeyman. The gentleman handling the paperwork kept using the word dispatch. I'm not a project guy I'm being hired to start up type work. I tried to clarify it and I kind of understood that if I was a pipe fitter or a welder I would get dispatch to a project. Since I'm not working along those lines does dispatch actually mean anything to me or my position?