Definition - What does Class Variable mean?
A class variable is an important part of object-oriented programming (OOP) that defines a specific attribute or property for a class and may be referred to as a member variable or static member variable.
Techopedia explains Class Variable
Because class variables apply to an entire class and all of its instances - even when a given instance also may have its own variables - there can be confusion about the interaction of class variables and variables limited to an individual instance. In terms of programming, common questions involve when to define class variables and instance variables, and whether these two different types of variables have the potential to overlap or affect each other in an unforeseen way. Even though some code works without a specific definition of class variables, professionals often regard the addition of class variables as more accurate coding.