The law of supply says that a higher price usually encourages producers to offer more for sale.
The principle assumes other relevant conditions remain unchanged, including production costs, technology, taxes, and the number of sellers. A higher market price can make additional production profitable, so firms may increase output and new suppliers may enter.
The law describes movement along an existing supply curve, not a shift of the entire curve. For example, a fall in wages or an improvement in technology shifts supply, while a price change changes quantity supplied.
The relationship is usually shown with an upward-sloping supply curve. It is a general tendency rather than an absolute rule: capacity limits, expectations, perishability, and unusual production conditions can make short-run supply less responsive.