Dictation vs transcription shows up in product design. A dictation tool needs a fast trigger, text injection into the focused app, and cleanup that makes a sentence look sendable. A transcription tool needs long-form stability, a way to review a recording, and often export formats. Latency budgets differ: a dictation user notices a half-second wait after every sentence; a transcription user may accept minutes to process an hour of audio. Speaker diarization matters much more for a multi-person recording than for a single person drafting email.
The overlap is real. You can dictate a paragraph and also keep a local history of that utterance. You can transcribe a lecture and paste a passage into notes. Some apps try to do both. Confusion starts when a meeting product is sold as dictation, or when a dictation hotkey is expected to label speakers on a conference call. Read the job: are you writing, or are you documenting a conversation that already happened?