GSA Schedule Contractors: CTA or Prime/Subcontractor Relationship?

"Under a Contractor Team Arrangement (CTA), two or more GSA Schedule contractors work together to meet ordering activity needs. By complementing each other's capabilities, the team offers a total solution to the ordering activity's requirement, providing a "win-win" situation for all parties."

But what is a Prime/Subcontractor relationship and what is the difference from a CTA? Let GSA explain.

See the information at gsa.gov.