Invented by Henry Cort, puddling is an historic process for refining which metal?

Henry Cort (c. 1740 – 23 May 1800) was an English ironware producer although formerly a Navy pay agent. During the Industrial Revolution in England, Cort began refining iron from pig iron to wrought iron (or bar iron) using innovative production systems. In 1784, he patented an improved version of the puddling process for refining cast iron although its commercial viability was only accomplished by innovations introduced by the Merthyr Tydfil ironmasters Crawshay and Homfray.

Iron is a chemical element with symbol Fe (from Latin: 'ferrum') and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust.