Irons, used to press the wrinkles out of clothes with the use of heat, have been around for centuries. While they continue to follow the same basic operating process, modern irons incorporate steam as a way of efficiently pressing clothes while minimizing the risk of scorching them.

The sole plate, or base, of the iron is flat and roughly triangular in shape. The modern metal of choice for sole plates is aluminum coated with a non-stick material. The sole plate, which is heated and applied to wrinkled clothing, allows a user to concentrate on small areas that need extra attention.

Modern flat irons have thermostats built into them to let a user control the sole plate temperature. More delicate fabrics require little heat while heavy duty fabrics require much more heat. The thermostat is essentially a spring with power contacts on the end mounted on a metal post. Electricity passes through the contacts to heat the sole plate.

The water to create the steam is stored in the reservoir. When a user presses a button on the iron to release steam, the water is superheated and released as steam.

Manufacturers generally make modern steam iron handles from injection-molded plastic that won't melt. The handle, which allows a user to handle the iron without being burned, also holds the controls for the thermostat and steam release.

Most irons have a power cord to access electricity needed to heat the water to steam and to heat the sole plate to the desired temperature. The power cord can sometimes make it awkward to move the iron around.