Classes and objects are fundamental concepts in Object-Oriented Programming. A class is a blueprint or a template for creating objects, which are instances of the class. An object is an instance of a class, and it has its own set of properties and methods.

In Python, we define a class using the class keyword. Here is an example of a simple class:

class Dog:
    def __init__(self, name, breed):
        self.name = name
        self.breed = breed
    
    def bark(self):
        print("Woof!")

In this example, we define a Dog the class that has a constructor method __init__ which takes two arguments name and breed and initializes the name and breed attributes of the object. We also define a method bark which prints “Woof!” to the console.

To create an instance of this class, we can simply call the class and pass the required arguments to the constructor:

my_dog = Dog("Buddy", "Golden Retriever")

This creates an instance of the Dog class with name set to “Buddy” and breed set to “Golden Retriever”. We can then call the bark method on my_dog:

my_dog.bark()  # Output: "Woof!"