There are 4 big clouds? I had only ever heard of the big 3 mentioned until now (AWS, Azure, GCP). From a quick search, appears that the 4th is Alibaba Cloud.

In the non-Chinese market, the 4th cloud is Oracle Cloud (OCI).

But yea, there is AWS, GCP, Azure, and OCI outside China and Alibaba, Huawei, and Tencent within China.