What is the difference between two Credential use options "VPN and apps" vs "Wifi" when installing a custom certificate on an Android emulator?

Solution 1:

The WiFi option is for authentication WiFi networks, while VPN and apps is for authenticating certificates for SSL/TLS communication for apps including the browser.

I can also confirm that VPN and apps is the right choice for proxying HTTPS requests for an Android device in Charles.

You can use digital certificates to identify your device for a variety of purposes, including VPN or Wi-Fi network access as well as authentication to servers by apps such as Email or Chrome. If you plan to use certificates for Wi-Fi authentication, be sure to select the Wi-Fi option from the menu described below.

Source: https://support.google.com/nexus/answer/2844832?hl=en