### Context
-Context is a core functional class that maintains the normal work of each component in the Android program
-ontext must participate in operations such as loading resources, starting Activity, obtaining system services, creating Views, etc.
-ntext provides global information about the application environment The interface
-an activity, service, and application context are all a new contextImpl object
-the number of exts is equal to the number of activities + the number of services +1/application
Between applications, the interaction and data transfer between application internal components
According to the description of the intent, find the corresponding component, complete the jump operation, and transfer data
## Intent
Interaction and data transfer between applications and internal components of applications
According to the description of the intent, find the corresponding component, complete the jump operation, and transfer the data
PendingIntent is a encapsulation of Intent, but it is not to perform a certain behavior immediately, but to perform a specified behavior after satisfying certain conditions or triggering certain events
Show the difference between Intent and implicit Intent
For Intents that clearly indicate the target component name, we call them "Explicit Intents".
For Intents that do not clearly indicate the name of the target component, they are called "implicit Intents".
For implicit intents, when defining an Activity, specify an intent-filter. When an implicit intent object is matched by an intent filter, three aspects will be referenced:
Action (Action)
category (Category ['kætɪg(ə)rɪ])
data (Data)
#### Android details-with Intent, why is there a Bundle?
https://www.jianshu.com/p/e9db0797293b
Toast
https://juejin.im/post/6864766325500149767