Terminology
Render
Drawing every frame of a composition and encoding them, with the sound, into a video file.
To render is to draw each frame and write the result to a video file.
# was: remotion render
npx kinetograph render src/index.tsx --comp CardWithout -o the video goes to out/renders/<comp>.mp4, with the extension that --codec gives. With -o, the extension sets the container: .mp4, .mov, .webm or .gif. The codec is H.264 unless you ask for another with --codec: h265, prores, vp9 or gif.
Useful options are --range 0..60 for part of the video, --draft for half size and --strict to fail on content the engine cannot draw. Studio has an Export button that does the same job and keeps a queue of renders.