here's my attempt at explaining it (in a short few paragraphs - I'm not the best at explaining things though):
Objects, in a nutshell, is a type of data that allows you to gather data and functions all under a single variable. Think of it as a collection of correlating information, a grouped and contained system if you will.
Classes can be viewed as the blueprints in which objects come from (called instantiating a class). Or you can think of this as a cookie cutter / template. It basically about reusability (with a few other benefits as well).
You can create a bunch of loose variables to represent something (say a car.. you need a variable for the car's brand, colour, number of doors, transmittion, etc..). But these variable are procedural. It makes reusing quite poor, as well as letting anyone go into the code and set things in a poor manner... If you build a class of a car (which contains all the variables (properties) and functions (methods) within it, you can simply create a single new object by instantiating the class. As a result, this object contains everything about the car all collectively under one roof so to speak. As a result, you can keep creating new objects off this car class, each with their own values based off of a central collection of variables and functions.
Additional advantages of classes is that you can have tight control over how object properties / methods are accessed. You can make properties / methods vary in visibility by making them either public, private or protected. If not public, this means that not just anyone can go into the code and set things procedurally.. this forces aspects of an object to be setup in a controlled manner..
As well, classes can have children 😉 (by this, I mean, you can have classes extend off of other classes, thus potentially inheriting the parent class' attributes (which again plays into reusability).
There's more (abstract classes, interfaces and whatnot), but that starts to get more deeply involved. OOP is a large enough subject in its own right. Learning it would serve you well. I'm sure other members here could explain things better, as this is not quite my forté, but hopefully, this gives a glimpse as to what is going on.
