Every ticket that comes in belongs to a single type, and this is where you can define them.
You may create a ticket type for support requests, one for sales enquiries, another for HR Requests, another for internal bug reports or anything else that you plan on using Issuebear for.
For each Ticket Type you can control which fields should appear on the form. Support Requests may need to ask the user for the Urgency, but Sales Requests might not.
On the main Ticket Types listing page you'll see a list of all available Ticket Types for your system. Everyone starts with a single default Ticket Type, and you can add more as required. See Managing Ticket Types for more detail.