You want to know what classes and objects are and the differences between them.
Classes and objects are at the core of Object-Oriented programming (OOP). A class is a blueprint or template for creating objects, and objects are instances of a class.
Structured programming aims to solve problems with functions. OOP solves them with objects. Think of objects as custom data types. Classes give programmers a means to define their own data types.
Your pet dachshund is an object of the Dog class.