A class is a combination of data methods or functions that can be instantiated as objects. A class is often used in OOP, and usually has its first letter in caps. Another definition is that a class is a construct that is used as a template or blueprint to create objects of that class. That object of a class is called an instance of that class. The template is a blueprint for the characteristics and behaviors that all the objects of that class share.
An object is an instance of a class. OOP (Object oriented programming) uses objects and classes. An object is bunch of characteristics, properties, or functions all contained within that objects class.
Multiple data items that can be selected by their given place with the array throughout a running program. Or more simply, an array is list of data. Each piece of data contained within an array is identified by an index number depending on is position in the array. The first element in an array is always , the second is , etc... Each array has a given length which is dependent on the number of elements within that array.