Grid mode, shuffle mode, spot mode and slip mode.
 

I dont really understand the differences between these modes. I have searched a little on the internet a little but still dont have the full understanding.

Can anyone explain basically what the modes are about and what they do? I would be thankful :)

Re: Grid mode, shuffle mode, spot mode and slip mode.
 

see Help/ProTools Reference Guide
page 445 (Chapter 23 - Edit Modes and Tools)

Re: Grid mode, shuffle mode, spot mode and slip mode.
 

Heya!

There is 2 Grid Mode :
Absolute :Each time you move a region its beginning will be set On the grid, depending the grid resolution you've chosen.
Relative: Each time you move a region in this mode, regardless of the exact beginning point of you region, it will be move 1 bar, 1/2 bar, 1/4 bar....i.e if you have an Attack which is just before, let's say 20ms before the Transient, if you move it 1 bar backward in Relative Grid Mode, the beginning of the region will be set 1 bar earlier minus 20 ms before the Absolute Grid.

Shuffle Mode: When you delete a region in between two contiguous, the third one will shift to the left and will stick to the end of the first one. Doing this on all the tracks at the same time will have the same effect as using the Cut Time Function.

Spot Mode: Each time you use the Smart tool in this mode, a dialog box will appear.
This mode is used when you need to move, trim a region very accurately by entering numeric datas.

Slip Mode: Pure Freedom!

Note you can associate two mode at the same time.It rare but you'll find some situations you'll need that.

Hope it helps.