No, the video you are about to see wasn't rendered by a powerhouse server farm, and most importantly, it's not a gigantic 20GB+ file. It was generated in real time by a tiny algorithm by demoscene group Mercury. This mind-blowing 64k intro is called The Timeless, and according to Gizmodo, "since the file size is limited to 64 Kilobytes, the graphics and music are all generated algorithmically in real time (procedural generation)." Continue reading for the clip.
Procedural generation is a widely used term in the production of media; it refers to content generated algorithmically rather than manually. Often, this means creating content on the fly rather than prior to distribution. This is often related to computer graphics applications and video game level design. The modern demoscene uses procedural generation to package a great deal of audiovisual content into relatively small programs. Farbrausch is a team famous for such achievements, although many similar techniques were already implemented by The Black Lotus in the 1990s.