The invisible hand is a concept discussed in Adam Smith’s 1776 book titled An Inquiry into the Nature and Causes of the Wealth of Nations. The invisible hand exist in free markets. It’s the unforeseen force that allows product and service prices to find their natural equilibrium. This is in contrast to planned economies or those that are heavily government-regulated.
An example of the invisible hand is a product that a seller prices high and is unable to sell. The seller drops the price until people begin buying. Adam Smith would say the invisible hand is at play here. It also works in the other direction. If a product is priced too low, the manufacturer will sell out unless the price is raised. In both cases, supply and demand find equilibrium.