Welcome to the world of Maximo Harold!
The short answer is both.
Depending on your role within the organization and how your organization has developed its processes, you could create a Work Request/Service Request which can then be reviewed prior to being converted to a WO. Or you can create a WO straight away. Typically, users within maintenance create WOs while those external to maintenance create Work or Service Requests with the intent of reducing the number of unneeded or unwanted WOs in the system.
Normally, the process should be designed so the user performs the least number of steps required to accomplish the desired results with as little downstream impact as possible. We have some clients that create WRs/SRs and/or WOs from screens, emails, mobile devices, and/or based on sensor or meter inputs (like temperature gauges or water meters), not to mention that WOs can be automatically created by and for other means (like Preventive Maintenance).
The processes (and the system supporting it) can be streamlined so that a work request can be automatically routed from the requestor to the responsible maintenance person's cell phone within minutes of the request if needed.
I hope that answers your question, if not please let me know.
Best of luck Harold on your Maximo journey!