Waxes are characterized as much by their properties as by their exact chemical composition. Generally, waxes are hydrophobic (water-repellent), lipophilic (fat-loving), solid at most ambient temperatures (jojoba oil is an exception), but malleable and with a low melting point.
In nature, wax has pretty much one purpose: waterproofing. Bees use it to construct structural cells that will contain liquid. The wax found on the leaves of the carnauba palm, wax myrtle, and candelilla plant prevent excessive moisture loss. And so on. Humans have long known of the value of wax: as a waterproofing agent, as fuel (as in candles), as a cosmetic skin emollient, a lubricant, a food coating (think of those nice shiny candies and apples), and crayons.