The Balkans are countries in the Balkan Peninsula (European southeast), such as Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Kosovo, Montenegro, North Macedonia, Romania, Serbia, Slovenia, the West part of Turkey.
Some are present members of the EU. Some are included in the Schengen trade area.
Eastern European countries are anything east of Hungary and Germany, most of them border Russia, directly.
There are recent changes in Europe due to Brexit taking effect in many forms of policy changes as well as in resources (oil, gas, mined materials) involving these regions.