The Bronze Age (THE FURY OF FIRESTORM, 1984)
In her original incarnation, Felicity was a supporting character for the Super Hero Firestorm, Ronnie Raymond. She worked as a supervisor in a software firm and eventually developed a romantic relationship with Ed Raymond, Ronnie's father, without knowing Ronnie's secret identity.
Despite her close relationship with the Raymond family, Felicity didn't believe that Firestorm was a hero at all, and instead thought he did more harm than good and would often endanger lives as collateral damage.
Re-Invention (ARROW, 2012-Present)
In a dramatic departure from her comic book roots, Felicity was reimagined to be a supporting member of "Team Arrow," a term she coined herself upon discovering the identity of her boss, Oliver Queen, as Green Arrow -- the vigilante protector of Starling City.
In this version of her story, Felicity was an M.I.T. graduate and brilliant hacker, tasked with technical support and engineering for Oliver's extracurricular vigilante excursions. Introduced first as an intern for Queen Consolidated (ARROW season 1, episode 3 2012), Felicity rapidly went from side-character to integral member of the team as she proved her skills invaluable to Oliver's operation, both in and out of the costume.
Felicity eventually became Oliver's Executive Assistant to help continue to provide cover for his time spent as the Arrow (Arrow, season 2, episode 1, 2013), a position that also allowed her to begin networking with people outside of Starling City. She met and became friends with Barry Allen, aka The Flash, and the two began maintaining a close friendship that would form the start of a network of Super Heroes operating between Starling and Central City.
Following Ray Palmer's acquisition of Queen Consolidated (Arrow, season 3, 2014) Felicity began working with Ray to help develop his experimental Atom suit, which would eventually result in him becoming the Super Hero known as The Atom. Around this time, Felicity and Oliver began to attempt a romantic relationship, but Oliver found his dedication to his life as Green Arrow prevented him from committing -- though an attempt at retirement to Ivy Town gives them both a chance to start over.
Despite a brief period of normalcy and their temporary retirement to Ivy Town, both Felicity and Oliver were called back to Starling City -- now called Star City -- to resume their duties as Team Arrow (Arrow, season 4, 2015). Felicity was promoted to CEO of Queen Consolidated, now Palmer Technologies, but during an ambush targeting both she and Oliver, she was shot and paralyzed from the waist down leaving her temporarily wheelchair bound (Arrow, season 4 episode 10, 2015). This tragedy did not, however, force her into retirement from the Super Hero business and inspires Oliver to give her the codename "Overwatch" as she resumes her duties as the team's tech support.
Following her full recovery with the aid of a spinal implant, Felicity was fired from her CEO position at Palmer Tech, and is left struggling with the collapse of Team Arrow after Oliver's many personal secrets and long list of enemies come back to haunt the team.
Eventually, Felicity and Oliver decide to marry each other (Legends of Tomorrow, season 3, episode 8, 2017). They held a joint ceremony with friends Barry Allen and Iris West, conducted by Oliver's long time ally and fellow Super Hero, John Diggle.