Binaural beats
Binaural beats rely on two slightly different tones presented separately to the ears. The perceived difference emerges from binaural processing, so stereo headphones are generally part of the setup.
Isochronic tones
Isochronic tones use a clearly pulsed sound whose amplitude rises and falls at regular intervals. The pulse exists in the audio signal itself rather than depending on separate left/right tones.
Which should you choose?
There is no universal answer. Consider listening comfort, the specific protocol, available evidence for the outcome you care about, and whether headphone use is practical. Avoid assuming that one method is inherently more powerful based only on marketing language.
Next steps
Read the entrainment guide for the broader mechanism and meditation audio for a goal-oriented view.