Speaking to a customer recently, an inventor type of person, realised I was confused by all the different terms he was bandying around. Possibly because he was confused as well.
So went through to reduce my confusion.

Patents

You tell the government about your new new improved process, machine or invention. They grant you the exclusive right to use that for a set period. In return everyone can find out about your invention so the public good benefits. In the future people can take incorporate the knowledge in your patent. You have to apply, go through an approval process, pay and keep paying.

Registered Designs

Similar rights as a patent but about the visual design, decoration and shape. Again for a limited time, years. your distinctively shaped chocolate bar perhaps. Toblerone perhaps.

Trade Marks

Stops your identifying mark being used by someone else, so it stays distinguish to your product from others. Stops me setting up Bryan Air ^™ as a low cost airline. Does in theory last forever if you keep defending/paying fees.

Trade Secrets

Your secret sauce, your Mums secret recipe for that pie she makes. Relies on secrecy, if I find her recipe book there is little legal problem for me using it. Think the secret recipe for Irn-Bru.

Copyright

Prevents copying of work, varying lengths of time, for a book, a film or music recording this can be a long time. Copyright does exist automatically, without an application process.

The onus is on you to protect your patent, trademark or copyright. No one else is going to pursue those contravening your rights.

All these rights seem to vary across the world, with different rules and schemes. You would potentially have a completely valid patent for your invention-o-matic in the UK but need a different patent and process in a different countries and regions (Europe, America etc). Although some countries have trade agreements to cooperate.

Hopefully I’ll have a better but still admittedly partial understanding next time I’m talking to an inventor.