SA Depot

A Class
An individual class is shown on the diagram as a box with up to four sections:

The first section shows the name of the class. Names should be nouns. Typically the first letter of every word in a name is capitalized.
Attributes represent the state of the object or what the object knows.
Operators represent the behavior [...]

An object is an instance of a class and it is the instantiation of a class, i.e. it is the object created from the class at runtime. An object diagram shows specific instances of classes in a class diagram and links between the instances at some point in time. It can be thus viewed as [...]