Difference between entity type and entity set?

lets understand them all:

1.An Entity is a real world "thing" which have independent existence.

2.Entity type is a category.

3.entity type is strictly calling, "an instance of entity type".

4.An entity type defines a collection of entities that have the same attributes.

5.Entity set : the collection of all entities of a particular entity type in the database at any point of time is called Entity set.