The Global Gateway Virtual Terminal is an online payment application that allows you to accept credit cards and other payment types using your PC. The Virtual Terminal also acts as your Global Gateway account management application and allows you to view gateway processing reports, edit fraud settings, manage users, and more.
FD has their own in-house sales team, and they can sign you up directly. No need to go through a middle-man, unless that middle-man is going to offer you something above and beyond what FD can give you.
First Data is at the top of the food chain. They handle everything in-house, which means that if you sign up directly with First Data, then you deal exclusively with First Data. No middlemen.
They offer a ton of resources, tools and complementary services for their merchants. This includes tools that help with PCI compliance, transaction data & analytics, fraud prevention, chargeback dispute resolution the list goes on and on.