Reserve Squadron??

What is meant by “Reserve Squadron” these days.

I note that both the Tornado Reserve Squadrons have more aircraft than standard RAF squadrons – so I guess they need them all.

I see they are listed as Operational Conversion Squadrons – does it mean that the pilots & aicraft allocated to these squadrons are there on temporary assignment, while pilots are being converted to the Tornado, and could be pressed back into operational service at a moments notice?

I’m a bit confused.