vCenter License Administration; Apply the license! - Simple when you know

Ok, so this is actually a very simple topic / activity but it took me, a VMware rookie, a little while to suss out so I have decided to do a little blog post and perhaps it'll save someone some time in the future, or maybe just give me a giggle in a few years when I look back at this knowing more than I currently do.

Once you've installed your vCenter (vCSA) instance you will have the trial license installed with 60 days ticking down on the clock. Similarly, when you add a ESXi host into your vCenter inventory you will have an evaluation license, 60 days, ticking down. The free license which you get from VMware will not work when connecting the ESXi host to the vCenter server.

Licenses are installed in the licensing section, oddly enough!, but they don't actually take affect until you assign the license to one of your assets (the ESXi hosts or the vCenter Server itself). You can't just add the licenses and expect it to work, the added licenses are put into a pool, where they can then be assigned to an asset.

The licences section can be found here (in the vSphere Web Client):
Administration > Licensing > Licenses

There are 3 tabs in the pane, Licenses, Products and Assets. Licenses is where you add your licenses keys and then, once added, navigate to the assets tab, which shows your vCenter server and ESXi hosts, where you can then right click and assign a license to each of the hosts.