Steam engines, metallurgy, high fashion, and settings inspired by the Victorian (1837 – 1901) and Edwardian (1901 – 1914) Eras are commonly viewed as traits belonging to the steampunk subgenre. However, they are also part of steampunk's sister subgenre steampulp. The two subgenres are quite similar but differ in one crucial aspect: the punk element. Punk in literature means rebellion or resistance against social norms and ideals. Steampunk is defined primarily by its inclusion of the punk element. Steampulp however, is essentially steampunk without the punk. Steampulp does not focus on rebelling or resisting social trends and tend to be more story–driven than steampunk works.
For example, imagine a country where all manner of fantastic technologies exist, powered by steam. However, these technologies have led to great segregation between social classes as only the rich have these technologies. In a steampunk work, the protagonists will resist or rebel against the social norm (in this case, segregation). Maybe they are friends from different social classes or they plan to overthrow the government and make technology available to everyone (therefore eliminating the cause of segregation). A steampulp story might focus on wacky inventors, adventures using fancy technologies, or rebelling against the government due to living conditions (as opposed to the segregation/social norm).
History and classics
As steampulp is a fairly rare subgenre (and itself a derivative of steampunk), it is very difficult to determine exactly when it started. However, since steampunk was first formally introduced in the 1980s by Bruce Sterling and William Gibson, it's safe to say that any works from the 1980s onwards that lack a strong punk element but have otherwise very steampunk elements to it can be called steampulp. That being said, the two subgenres are closely related and a work that might count as steampunk to one person might be steampulp to someone else.
Steampulp classics can include the Wax and Wayne series by Brandon Sanderson (which tells the tales of two men, Wax and his best friend Wayne, as they investigate crimes, deal with political intrigue, and utilize metal-based magic in an industrial setting) and Perdido Street Station by China Mieville (about an eccentric scientist's encounter with a bird-like humanoid called a Garuda, resulting in a crazy adventure throughout the city as moth monsters get released). Outside of literature, the video game Final Fantasy 6 (about an amnesiac named Terra Branford who learns about her past, encounters a wide range of other characters, and uncovers a plot by a nihilist to destroy human life) by Squaresoft (Square Enix) is undeniably steampulp for its industrial setting, steam–powered technologies, and aesthetics.