No access is a gaming app that was used in 2016 by MAGA to influence the elections. MAGA has been driven off their platform by the executives who are not sympathetic to their extreme views. The best way to describe Discord is to imagine is Skype, Slack, Twitter Spaces and Microsoft Teams were spliced into a single app. Discord is built on individual servers which allows the server creator to have complete control (permissions, code design, bot integration,community moderation, etc).
They have text based chat rooms, audio based conferencing, Video calling, and screen share options as well as the ability to integrate bots to automate all aspects of server moderation. Furthermore these servers can be designed to bring in information from outside sources automatically by using RSS feeds to create webhooks. So any Tweet, Youtube video, RSS feed, etc, will automatically be brought into the server and then users can act on those notifications. MAGA used this effectively in 2016 to target news outlets comment sections to overwhelm their users with negativity.
Pete Buttigieg was able to win the Iowa Caucuses because he had a Discord server that gave him a community of thousands of engaged volunteers who could be surrogates for him across the US.