How to Compare Engineer Mode and User Mode Terminals

Eng mode terminal (it is also called engineering mode terminal, development terminal, dev mode terminal):

1. It's used by the application developer.
2. ADB exist in such terminal for easy developing process.
3. It does not authenticate the certificate of the APK's signature, so you can install any application to terminal.
4. There are "engineering mode" watermark in the bottom corner of the screen.

User mode terminal (it's also called production terminal, end-user terminal):

1. It's used by the end-user.
2. There is no ADB in production terminal.
3. It authenticate the certificate of the APK's signature. If the APK is not signed by the terminal's App root certificate or its sub certificate, it can not be installed to such terminal.