Sure, want one?
Water, the blue, drowny, non burny stuff. Drinking this is inadvisable, may contain carp.
-Created.
-Looks around and scratches its head a bit.
-Tries to flow in any orthogonal directions: ><^v, or down a z-level.
-If it can't, it randomly decides to go diagonally or teleport.
-If diagonal, it will essentially delete itself and create a tile of water in the diagonal area at its z-level: This is why water flowing diagonally will lose its pressure.
-If teleport, it will teleport through 7/7 water to the nearest empty spot, or partially filled spot. This is the brook u-bend effect.
Magma. The red, glowy, burny stuff. Drinking this is inadvisable.
-Created.
-Looks around and scratches its head a bit.
-Tries to flow in any orthogonal directions: ><^v, or down a z-level.
-If it can't, it will go diagonally.
-If diagonal, it will essentially delete itself and create a tile of magma in the diagonal area at its z-level: This is why magma flowing diagonally will lose its pressure.
-It doesn't do teleportation, hence, the lack of 'pressure' which occurs when water teleports through other 7/7 water.
These rules are applied for each tile of water or magma. When pumped, the tiles coming out of the pump will behave like that of water, teleport and all. So contary to popular citation, magma doesn't strictly become pressurized when pumped, it's the tiles pumped by the pump alone which are pressurized.
I think that covers everything.