Signal is a cross–platform, encrypted messaging service developed by the non–profit Signal Foundation. It is widely considered the industry standard for secure communication due to its strict adherence to the Signal Protocol, which provides end–to–end encryption for text, voice, and video calls. Unlike commercial competitors, Signal does not collect metadata, such as who you are messaging or when, and it contains no advertisements or trackers. The application is entirely open–source, allowing the global security community to regularly audit its code for vulnerabilities. For organisations prioritising privacy, it offers a secure alternative to proprietary platforms that monetise user data.