Is there a difference between eastern grey kangaroo and kangaroo?

Yes, there is a difference. "Kangaroo" is a general term referring to any member of the family Macropodidae, which includes a variety of species like:

* Eastern Grey Kangaroo: This is the most common type of kangaroo, found in eastern and southeastern Australia.

* Red Kangaroo: The largest kangaroo, found in drier parts of Australia.

* Antilopine Kangaroo: A smaller kangaroo found in the northern parts of Australia.

* Wallaroo: A smaller kangaroo with a more robust build, found in a variety of habitats.

So, while "kangaroo" refers to the entire family, "Eastern Grey Kangaroo" is a specific species within that family.