What's the difference between "Old Testament" and "OT (Hebrew Order)"?

From the perspective of posting a meditation, there is no difference. If you have a meditation on Exodus 12, feel free to list it under "Old Testament | Pentateuch | Exodus" or under "OT (Hebrew Order) | Law | Exodus".

Whichever you chose, the meditation you create will be listed under both those sections. The Hebrew order of the Old Testament offers another way for readers to navigate the site. That is all!