If written with capital letter (
Central Europe), it means a cultural region, traditionally including countries between France and Russia. It can be understood as fluid, but generally makes sense on many levels and includes:
Germany, Poland, the Czech Republic, Switzerland, Austria, Ukraine, Hungary,
Belarus, Slovakia,
Liechtenstein, Luxembourg...
In geographical meaning (
central Europe), most Central European countries (like Switzerland, Poland or Germany) are entirely and quite deep in western Europe (geographically). The meaning of the word "central Europe" becomes a bit more fluid (depending on a definition of a centre), but usually includes: Lithuania (centre of gravity), Hungary (geometric midpoint), Estonia (if all the islands of Europe – from the
Azores to Franz Joseph Land and from
Crete to Iceland – are taken into consideration). You can call all countries around it (to a certain radious) central European.
A common mistake is to
relegate c/Central European countries into "E/eastern Europe". That is offensive and ignorant not only for people in or from the countries but also well-educated people elsewhere.