Editing & Post-Production
Hardware encoding
Also called: NVENC, GPU encoding, Quick Sync
NVIDIA calls its version NVENC, Intel calls it Quick Sync, and Apple builds media engines into its own silicon. The chip is fixed-function, designed for one job at high speed, and it leaves the processor free for everything else, which is why live streaming depends on it almost universally.
Software encoding through the processor still holds an edge in quality for a given file size, though the gap has narrowed with each hardware generation and is hard to see at the bitrates YouTube accepts. Use hardware for streaming and quick turnarounds, and software when you are squeezing an archive master into a small file.