Video switcher

A switcher takes several inputs, cameras, a laptop, a games console, and lets you pick which one goes out, with transitions, picture-in-picture and lower thirds handled on the way through. Blackmagic's ATEM Mini is the hardware most creators meet first, while OBS and vMix do the same job in software.

Hardware exists because it is predictable. It keeps running while the computer is busy encoding, it shares nothing with your editing software, and the controls are physical buttons you can find without looking down. Software is cheaper and far more flexible, and it puts an entire broadcast on one machine.