Which is odd because the first time I heard the term DVR was in the late 1990's, referring to the box that was used to record TV signals digitally for playback

Which is odd because the first time I heard the term DVR was in the late 1990's, referring to the box that was used to record TV signals digitally for playback and/or ad-skipping. The term distinguished it from things such as VCRs, which recorded in analog, on tape. Those DVRs were, in fact, digital.