When it comes to OTT, it has traditionally been for the viewing of linear programming – which is the broadcasting of programs in their original order over a specific period of time. VOD offers more flexibility with programming and viewing options, such as the ability to binge watch series in a row or finish watching an episode that was missed due to timing.
Source: https://www.vplayed.com/blog/difference-between-ott-and-vod-streaming/