From DVD to stream
Netflix started by renting DVDs by post. In 2007 it launched streaming and became a global giant that now makes its own films and series. Spotify changed music: instead of buying albums you pay a subscription to the whole library.
How it works
Video is stored in several qualities, and the player switches smoothly between them depending on your connection. Content is delivered from servers near you (a CDN), much like Cloudflare does for websites.
Creators
YouTube and Twitch created a new profession: content creators and streamers. Many gaming streamers who broadcast games such as Rainbow Six Siege or CS2 have bigger audiences than TV channels.