Every Activity in Android is a Process,or One Application is one process

Question

In this page, http://androidapps.org.ua/androidintro_ipc.html , intent switching between activities is described as Inter Process Communication. Now I am confused whether e

Answer 1

No the activities of one application don't run on a different process each. And actually, even different applications built by the same developer (if the same certificate is used for all applications) could run in the same process!

As the documentation says:

Application modularity – The Android system allows applications that are signed by the same certificate to run in the same process, if the applications so requests, so that the system treats them as a single application. In this way you can deploy your application in modules, and users can update each of the modules independently if needed.