I did lots of search, but I cannot understand what the difference between google ai platform and ml engine.
It seems that both of them can be used for training and deploying models.
Other words like google-cloud-automl, google ai hub are also very confusing.
What are the differences between them? Thanks
The short answer is: there isn't. In 2019 "ML Engine" was renamed to "AI Platform" and in time some services changed and expanded. To see what has changed, check the release notes, starting from around April. "Around", as they haven't left much trace that ML Engine ever existed.
Here's one of pull requests to "Rename Cloud ML Engine to AI Platform" for Python samples.