Resources and Generic Resources Clarity

I am trying to understand the use of Resources. They seem to exist in two spaces as Resources and Generic Resources, but cannot be used interchangeably. We leverage Generic Resources (Equipment and Employees) for Projects. I noticed when booking an Event, there is an option for Resources, but that is a completely different pool of information. I don't understand how is that leveraged.

If we are doing a hardware demonstration with a customer and I need to book a technician and and a piece of hardware through an Event, those are not reflected in the Resource Allocation Grid. So we would have the risk of double bookings. Currently we created a dummy project to book Resources. This will at least be reflected on our Allocation Grid.