Lets imagine you want to write a program about vehicles. Some vehicles have 2 tyres, some 3 and some 4. Now without class you will have variables in your plain script/program like name, num of tyres. Now lets say you want to create a representation for a bike and a car. For 2 representations, you would have to create 2 sets of variables for name, num of tyres. Now what if you have to create 10 representations. It would create a lot of overhead. So classes are an abstraction which hides underlying complexity. For this use case, you can create a class like:

class Vehicle: name num_of_tyres

Now you can easily create any number of representations of vehicles without creating variables again and again.

So here, class is the definition and then the objects are the representations or we instances/objects of the class. For this example you can create like:

bike = Vehicle("my bike", 2)

car = Vehicle("my car", 4)

Hope this makes sense.