Movement speed

Movement speed is the speed at which players and mobs move. It is determined by the block they are walking on, and can be affected by other factors.

Surface

The surface players and mobs are walking on determines their movement speed. Hard surfaces and those used in roads speed up movement, while soft surfaces don't. Hard to move through surfaces such as sand slow down movement, while soul sand and leaves slow movement even more. Partial blocks such as snow and ash slow down movement in addition to the movement speed modifier of the block underneath it. All blocks that speed up or slow down(except leaves and soul sand) movement do so by the same amount.