The foot is a unit of length in the imperial unit system and uses the symbol ft.
One foot is exactly equal to 12 inches. It is also exactly equal to 0.3048m. One yard is comprised of three feet.
The foot is just behind the metre in terms of widespread use due to its previous popularity. The US is the only developed country that still uses the foot in preference to the metre.
The UK still uses feet to express human height more than metres.
The furlong is a unit of length in the imperial unit system and uses the symbol fur.
One furlong is equal to 1/8 mile, 660 feet, 220 yards, 40 rods, 10 chains or ≈ 201m.
The furlong was a term used to describe the legnth of a furrow in one acre of a ploughed open field (communal field). It now only really remains in the world of horse-racing in UK, Ireland, Canada and the US.