Explain the difference between class and object

What will be an ideal response?

Class and object are often used interchangeably. And often, no harm results: class is an abstraction of similar objects and an object is a concrete manifestation of a class. (Sentences would become very awkward if everywhere we repeat "class and/or objects" or "class and its instances.") In majority of cases, what we say about classes also applies to objects, and vice versa. It is in those minority of cases that the distinction is crucial: class is the concept, object is the realization of the concept. Class is the cookie cutter, object is the cookie. If we declare that the cookie cutter is round, we imply that the cookie would be round, too. But if we say that we want to eat a cookie, it is unlikely that we mean to eat the cookie cutter as well.