Setting is defined as the "social environment, place and time" in which a story's events unfold (Literary Devices, "Setting"). The setting of a novel will consist of one general time and location, such as Paris during the French Revolution, but if a story takes place in multiple locations and times, then the setting will encompass those as well. Beyond place, time, and social circumstances, setting will include "geographical locations, weather, [and] immediate surroundings" ("Setting").
Robert Louis Stevenson's novella The Strange Case of Dr. Jekyll and Mr. Hyde is set in London during the Victorian era, a very morally restrictive era and the same era Stevenson grew up in. The moral restrictions of the era serve to help develop Stevenson's theme of the dual good and evil natures of mankind.
Beyond being set in London during the Victorian era, there are also more specific details that make up the setting. For example, the novel opens with Dr. Jeckyll's lawyer, Mr. Utterson, and Mr. Utterson's distant relation, Mr. Enfield, walking down a small "by-street," or private side street, in Soho, London. On the side street, they see a very uninviting door that Enfield has seen Mr. Hyde entering and exiting, using a key. Utterson happens to know that on the other side of this building is where Dr. Jeckyll lives.
Other aspects of the setting include where and what time of day individual scenes take place. For example, we learn of Dr. Jekyll's strange will in Utterson's house after dinner, and Utterson first approaches and speaks with Hyde in the courtyard in Soho at night.