Nichrome (also known as NiCr, nickel-chromium or chromium-nickel) is a family of alloys of nickel, chromium, and often iron (and possibly other elements) commonly used as resistance wire, heating elements in things like toasters and space heaters, in some dental restorations (fillings) and in a few other applications.
Patented in 1906 by Albert Marsh (US patent 811,859), nichrome is the oldest documented form of resistance heating alloy.
A common nichrome alloy is 80% nickel and 20% chromium, by mass, but there are many other combinations of metals for various applications.