What is a bot farm and what do Ilon Musk and neural networks have to do with it?

Who are bots and trolls, what is the difference between them, and how bot farms work — from mass purchase of accounts to the use of proxy servers and synonym selection services to create content. The goals of bots are also discussed: from artificially increasing traffic and advertising to forming false public opinion, which is especially dangerous in politics. The topic of AI technologies, which make bots increasingly indistinguishable from real users, is also touched upon.