Life span - also known as life expectancy or life cycle - was the amount of time an organism was expected to live based on its time of birth and other factors.
Prior to first contact with the Vulcans, the human life span was typically just under a century, or 100 standard years. By the mid 23rd century humans could live well past the age of 100. (ENT episode: "In a Mirror, Darkly") In the 24th century Leonard McCoy lived well past the age of 137. (TNG episode: "Encounter at Farpoint")
Vulcans were well known for their extended life spans. By the 24th century life spans in excess of 200 years were not unheard of. Ambassador Sarek lived to the age of 203 before passing away from Bendii syndrome. (TNG episodes: "Sarek", "Reunification") T'Pau was still alive in 2376 at the age of 254. (NF - Excalibur novel: Renaissance)
The maximum life span of the Klingons was something of a mystery as many Klingons died violent deaths while still young. However many Klingons lived well over a century, including Kor, Kang, Koloth, and Darok. (TNG novel: Strike Zone; DS9 - The Left Hand of Destiny novel: Book One; DS9 episode: "Blood Oath")
When Benjamin Sisko encountered the Gorn individual who James T. Kirk had encountered on Cestus III over a century earlier, Sisko commented that he did not think the Gorn life span was of that length. The Gorn had been kept alive by the Metrons. (DS9 short story: "Where I Fell Before My Enemy")
Life spans of creatures included twelve thousand years for a Grumpackian tortoise, the Misian bogfly at twelve hours, ten weeks for a tube grub and twelve years for a wooly slug. (DS9 novel: Legends of the Ferengi)