A class is a template for creating objects, while an object is an instance of a class. A class defines the attributes and methods that an object has, while an object is an instance of the class with its own values for the attributes defined in the class.

A lambda function is a short, anonymous function that can take any number of arguments, but can only have one expression. It is used for situations where a function is required, but the code is too simple to justify creating a separate named function.