WebRTC (Web Real-Time Communication) is an open-source project that enables real-time communication (RTC) capabilities in web browsers and mobile applications. It allows for video, audio, and data sharing between browsers and devices without the need for plugins or additional software.

VPN stands for Virtual Private Network. It's a technology that creates a secure, encrypted connection over a less secure network, such as the internet. VPNs are commonly used to protect sensitive data, browse the internet privately, and access restricted websites or services.

A proxy acts as an intermediary between a user and the internet. It hides the user's IP address and provides a level of anonymity while accessing websites or services.

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Its primary goal is to establish a barrier between a secure internal network and untrusted external networks, such as the internet, to prevent unauthorized access while allowing legitimate communication.

MAC stands for Media Access Control, which is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment.