Some free streaming platforms offer both live and on-demand content, or only one type. If you like to channel hop, then a service like Pluto may be your first pick over Tubi or Freevee. But because they're all free, you can get more than one without hurting your wallet.
The services that stream regular cable channels include AT&T's DirecTV Stream, the sports-focused FuboTV service, Hulu + Live TV, Philo, Sling TV, and Google's YouTube TV.