Tangled is an adjective that describes a confused mass. You're likely to hear tangled used most often when referring to hair. If it's tangled, you can't brush or comb through it.
Other than discussing hair, tangled can be used to refer to anything that's jumbled up and confused. Like that tangled pile of wires behind your television and computer that you keep tripping over. Tangled can also mean something highly complicated or intricate, like the relationships between ex-wives, ex-husbands and stepchildren in a family. The word tangled is most famous for being included in a well-known literary quote from Sir Walter Scott's poem, "Marmion" — "Oh what a tangled web we weave, when first we practise to deceive."