How to discard items in inventory for minecraft? (not hotbar)?

Just wondering,
here's a video of Bajan discarding items out of his inventory…
watch at 6:09

Thanks in advance.

Added (1). BTW. I wanted a key to make it faster than just pull it out and click on open space, ty.

Guest

Click the item in your inventory and click the area outside of it. I know you don't want hotbar but if you need it, pull it out in your hotbar and press Q. Also, a few other tips you might've been looking for, to instantly switch items between your inventory and any type of storage, press shift+click.

Alexander