A wheelbarrow is a small, hand-propelled cart designed to carry moderately sized loads. Its structure distributes the weight of comparatively heavy loads, allowing an operator to move loads that would be impossible to lift or maneuver without some type of assistive device. Wheelbarrows can be seen on construction sites and in gardens, among many other places, and most hardware suppliers stock them in a variety of shapes and sizes.
The basic design of the wheelbarrow has not changed very much over the centuries. It is made up of a deep tray or platform mounted on lightweight frame. One end of the frame has one or two wheels, while the other end has legs and a set of handles. When the wheelbarrow is in a resting position, the legs keep it upright; when it's in motion, the user lifts the legs up with the handles and pushes or pulls the load, with most of the weight balanced on the wheel rather than in the hands of the operator.
There is some dispute as to who invented the wheelbarrow. Archaeological evidence suggests that it was used in Ancient Greece as early as the fourth century BCE, and adopted by the Romans. Some people claim that the Chinese invented the device, however, although the earliest one known to have existed in China dates to around the first century BCE. It is entirely possible that both cultures came up with the idea independently, in which case both could share the fame.
The wheelbarrow is such an iconic garden tool that it has even been immortalized in a famous William Carlos Williams poem, in which the author muses on a red one in his distinctive minimalistic style. In addition to being subjects of poetry, wheelbarrows are also extremely useful. Most are lined so that they can carry wet or dry goods, and those used for gardening may have especially broad wheels so that they do not damage lawns. Gardeners can use one carry dirt, plants, paving stones, cut brush, weeds, and a wide variety of other things, and some gardeners keep several sizes for various tasks.
In construction, the wheelbarrow is also a very useful tool, and evidence suggests that it was probably originally devised for carrying heavy construction materials like bricks, broad beams, cement, and quarried rock. It can also be used to transport wet concrete, construction debris, and an assortment of other items; typically, if it will fit into a wheelbarrow, it can be moved with it, although really heavy items might require the work of two people.