The Western and Eastern Europe division refers to capitalistic and former communist countries and that's why it's so largely used by whoever around prior to 1989
Indeed, 1989 is a distinct mark for it. But the division itself goes back much deeper into history, as far as to the Kingdom of the Franks as of the year 801-870. The eastern border of their empire was on the river Elbe. Much later on, historians, intellectuals and politicians still considered the river Elbe as the economic "border" between Western Europe and its eastern borderlands. Even Marion Hedda Ilse Gräfin von Dönhoff, the long-time editor of Die Zeit
who died in Germany 2002 but was born in Friedrichstein, in today's Kaliningrad enclave of Russia, used to see this distinction very clearly in the 20th century. She used to say that as a former Prussian aristocrat she felt more at home in Poland than in West Germany at the time West Germany still existed.
Of course, the countries bordering the former Regnum Francorum to the east have been under the influence of the so-called West for many centuries and adopted many things from that "West", so the term Central Europe
had been slowly coined to describe those lands between the western part of Germany and Russia. In literature you can easily find academic discussions dividing this Central Europe area even further, that is into the central-western and central-eastern Europe. So those claiming the division between the two "Europe's" had been achieved simply as a result of the Worl War II are wrong and should read more on the subject in history books.
Clearly, the divisions from before the WW II were not as distinct as they had become after this war with so-called Iron Curtain having been erected between East and West. As a result the areas of Central Europe and Eastern Europe have been somewhat "merged" under the auspices of the Soviet Union and this common area started to be known as the "Soviet block" or "Eastern Europe". With the fall of the USSR and the development of the European Union to the east, we can safely say we are back again to the reality of old divisions with Poland, Czechia, Slovakia, Hungary in Central Europe, bordering Eastern Europe consisting of Ukraine, Belorus and Russia (to the Ural mountains). And if East Germany was not re-unified with West Germany (we shall remember that it was not certain at the time, for example British Prime Minister Margaret Thatcher was very much against it), it would have also been considered another Central European country.