How to Compare Engineer Mode and User Mode Terminals

Engineer Mode terminal, sometimes we said development terminal, develop mode terminal, that's the same terminal, here are the features:

Used for developing app.
Has ADB for easy developing process.
Do not verify the signature of the app.

User Mode terminal, sometimes we said production terminal, end-user terminal, here are the features:

Used for deployed app for the end-user.
Without ADB port in production terminal.
Forced to verify the app's signature.

   About the certificate,  it should be issued by the app root certificate. By default, there is default wizarpos root certificate in the terminal. So you can request production certificate to us for your keystore (which will be used to sign apk). The apply step is described in the document wizarPOSDevCertificateApplyGuide_en.pdf.
   After get the certificate from us, you should import the certificate to your keystore, then all the apk signed by this keystore can be installed to production terminal.
   Please notice, because of this difference, if your Engineer mode terminal switch to User Mode terminal, all the application you installed in terminal, which is also not signed by above keystore, will be removed automatically.
   Of cause, the default WizarPOS root certificate can be updated to terminal owner's root certificate in future. So the terminal owner can control their apk certificate by themselves.