Understand the building blocks.
When you sign in, you're brought to your list of flows. Think of a flow as a way to collect information to fulfill a specific goal within your organization: for example, a new user sign-up flow, a collecting-feedback flow, a matching-to-an-agent flow.
A responder is an end user of your flow - the person going through your flows and providing answers to your questions.
Every flow starts with a main variant.
Using Save as, you can create new variants. These can be wildly different from one another in terms of style and content, but should still have the same goal and collect the same information as the other variants in the same flow.
You might use a variant to try out a new visual style or a new content ordering of your questions, similar to how a developer uses a git branch to try out a new feature.
They help users measure progress towards completing the flow, and help you segment the information you collect and responses you provide to your users into logical fragments.
Groups are primarily an organizational concept for more complicated form flows, and by default, there is no responder-visible difference between steps in different groups.
Groups can be used to:
Within a step you can add one or more questions, which collect information and store the responder's answers to send to you, or use later within the same flow.
Questions may be rearranged within a step or between steps via drag-and-drop, and may be arranged within the same row as one another.