UK, and a few other countries in Eastern Europe + Russia. Since people might not know directly know what EEA means, it's easier to use Europe as generalization. (or to post a link with all the specific countries, such as Fandy did)
The UK is still part of the EEA, just not the EU (European Union). They are different things. Also, for purposes of regulations, even most EU regulations remain in effect in the UK until Dec 2020.