[Android Learning note] Context Simple Comprehension

A. What is the context?
A context object that can be understood as a running environment for a program from which you can get the resources of the current program:
Getresources,getassets

Two. What are the common context?
Application Context
Activity Context
Service Context
When creating a application, Activity, Service, it will create a context object that belongs to them.
Although different contexts in the same application have access to the same set of resources, the environment is the same, but their life cycle is inconsistent,
This makes it necessary to pay attention when using them, so as not to cause a memory leak

Three. How do I get a context object?
Activity.this
Getapplication
Getapplicationcontext