A Class is a user defined data-type which has data members and member functions.
* Data members are the data variables.
* Member functions are the functions used to manipulate these variables.
Classes in different languages:
* There are no classes in Go, but Go has struct types. Struct types plus their associated methods serve the same goal of a class, where the struct holds the state, and the methods provide them behavior.
* JavaScript classes are primarily syntactic sugar over JavaScript’s existing prototype-based inheritance. The class syntax does not introduce a new object-oriented inheritance model to JavaScript.
* There are no classes in Rust, but we have struct and impl so we can mix them to simulate a class.