A steam machine is primarily defined as a heat engine that performs mechanical work by utilizing steam as its working fluid. Beyond this fundamental engineering concept, the term broadly refers to various applications, including a steam cannon that launches projectiles using heat and water, and the practical process of steam cleaning.

In the realm of computing, "Steam Machine" specifically designates a line of pre-built gaming computers engineered to operate with SteamOS. Furthermore, the name extends to cultural works, such as the puzzle video game Heron: Steam Machine. The term has also inspired music, notably appearing as the title of a 2005 song by the iconic electronic duo Daft Punk from their album Human After All, and an earlier 1983 track by the band Freur.