End-to-end encryption, in simple terms, is encrypting or scrambling messages in such a way that they cannot be decrypted unless by the recipient. So the recipient receives the message in an encrypted form and decrypts it.
Private browsing works by simply blocking your browser from tracking your online activity whenever it is activated. For instance, when browsing privately, your browser will not save your browsing history.
A VPN creates a private network from a public connection that helps the user to hide their browsing history, streaming location, IP address, web activity, and their devices from their internet service provider (ISP).