Objects can be compared to the objects in the external world, such as your computer, your house, animals and plants. Ina an application you can have objects such as buttons and list boxes.
Most objects are made up of other objects - your house has rooms, doors, windows and so on. If we know that we can build a house by combining these objects then we do not need to worry about the design and structure of each object, which may be very complex. Similarly in object orientated programming (OOP) if we have objects which behave in a defined way, we can combine them together to make an application without worrying about what happens inside each object.
The difference between objects and classes is that many programmers become confused between objects and classes. A class is the defenition for a group of similar objects with similar properties. For example, a house, a flat and an igloo all belong to the building class. In OOP jargon, the objects belonging to a class are instances of that class