As I'm knowing Buddhism called atheism religion but I've doubt both are different, I call myself I'm an atheist as well as Buddhist. Or it just described what is it ?
Atheism is not a religion. It's just a view that says there are no deities. Atheism is harmless & compatible with Buddhism when it just means there is no creator/almighty God who is responsible for our fates. But it becomes extremely dangerous and contradictory to Buddhism when it grows into nihilism & materialism.
On the other hand, Buddhism is a comprehensive religion with vast number of texts containing in depth teachings and clear guidance on the nature of phenomena and their workings. It teaches the causes of these phenomena, what we need to aim for, and how to achieve that which needs be achieved.
These teachings include deities, non-humans, hells, heavens, rebirth, karma etc. & also guidance on how to make the household life successful. Buddhism also has rules & rituals associated with it.
Atheism & Buddhism are the same in that both do not believe in a creator god.
Atheism & Buddhism are different in that atheism does not provide a path to end suffering.
Buddhism and some theistic religions have some similarities in that both share some (moral) aspects of the path to reduce suffering.
Buddhism and Atheism, these two words although having some overlap, are contradictory for most people. Atheism is not Buddhism, Buddhism is clearly not Atheism.
Buddhism can be said to be Atheistic because of rejection of conventional notions of afterlife and creation but Atheism cant be said to be Buddhistic because Atheism is rejection of specific views and not a view itself.
As i see it Atheism is a counter opposite to Theism and rejection of theistic religious views. Atheism clearly communicates what it doesn't believe, rather than what it actually believes.
Buddhism gives totally new definitions to words like "god", "angel", "good", "evil", "death", "wisdom" which are common concepts in theistic religions. Therefor Atheism doesn't really apply very well to the framework of Buddhism as i see it, because they deal with same words but completely different meanings.