A controller at the telescope orchestrates everything: capture/sequencing (NINA — free, Windows; APT; SGPro; ASIAIR), mount control + plate solving, autoguiding (PHD2 — free, cross-platform), and autofocus. Integrated controllers like ASIAIR or Stellarmate run on a Raspberry Pi controlled from your phone. Processing happens later in PixInsight, Siril (free), or DeepSkyStacker (free). NINA + PHD2 is the free gold standard on Windows; ASIAIR suits a phone-controlled, self-contained rig.