What is the difference between the ARM and Hybrid loan type?

ARM (adjustable) and Hybrid could output the same with similar data entry.

The difference is that Hybrid can allow an IO period to be identified during the fixed period.

ARM lets the user identify fixed IO periods only.

Hybrid lets the user identify fixed period separate from the interest-only periods only.

Hybrid Rate Types, with additional settings, could also allow separate adjustable interest-only periods.

After completing the data entry, do check that the Timeline of the order matches your intention.