Discord (not to be confused with the literary term "discord") is an online instant messaging software, similar to Skype or TeamSpeak. Discord allows users to communicate through text messaging or voice and video calls, either in private messages or in chat rooms called "servers."
Discord was founded by Jason Citron in 2015, and was originally marketed towards gamers, as a means of communicating with others during gameplay. However, it would gradually rebrand itself as a communication platform for everyone.
Discord itself is free, however users can pay Discord every month to receive special features known as "Discord Nitro."
Discord is written in JavaScript, React, Elixir, and Rust. It is used by around 350 million people.
Discord's user-base is often stereotyped as gamers, weaboos, or furries (or all three). While there is likely at least one of these individuals in every public server, these are gross generalizations and do not reflect Discord's user-base as a whole.