Capacity carrying

What does it mean to be Heavily Encumbered:

All items in DDO have weight. the amount of weight a character can hold at maximun is represented by a bar below the inventory boxes. As the bar slowly fills from none to light to medium to heavily encumbered the character's speed and ability to perform certain actions is hindered. The amount a player can carry (weight wise) is governed by the Strength mod. the higher the strength mod, the more a character can carry. Most players will want to keep a weight below medium as most detrimental effects occur after medium encumbrance. Heavy will greatly slow character speed, and after heavy encumbrance one becomes overburdened and unable to act.