HOW TO TELL IF SNAP TO GRID IS TURNED ON

If you're wondering whether you have Snap to Grid turned on (found by pressing Command-J) for a particular window that's in Icon view, just look in the bottom left-hand corner of the window (just below the sidebar). If Snap to Grid is turned on for that particular window, you'll see a tiny grid icon. If Keep Arranged By Name is turned on instead, you'll see four tiny evenly spaced folder icons.

Snap to Grid icon

Keep Arranged By Name icon