How many different contexts exist in a specific scenario or system?

The number of different contexts in a system depends on the specific scenario and application architecture. In Java, for example, context can mean different things: execution context, application context (in Spring), servlet context (ServletContext), etc.

In Android, there are several types of contexts — Activity Context, Application Context, Service Context, etc. Generally, the number of contexts is determined by the number of components and levels of abstraction they represent.

Therefore, the exact number of contexts cannot be universally specified — it depends on the architecture and requirements of the specific system.