What it is for. The G703 worksheet for one job: the list of work items and what each is worth. This is the basis for every progress draw you bill, so it has to be right before the first application.
What you see. An editable table of line items — description, scheduled value — with the contract sum totalled at the bottom. Header fields carry the job, customer, contract date and address.
Change orders. An approved change order can be applied here, which raises the contract sum you bill against.
Do not also apply it to an invoice. Applying a change order to an invoice raises the invoice total; applying it here raises the contract sum. Nothing links the two, so doing both bills the customer twice for the same work.
What it connects to. Progress Billing, Pay Applications, Change Orders.