By the end of the 80's, thanks in large part to the "Revenge of the Nerds" movies, geeks & nerds were all of a sudden cool in pop culture. The producers of Family Matters found that out when they introduced America's Nerd, Steve Urkel (Jaleel White) in what was meant to be a 1-shot in the first season. Instead, Urkel became this generation's Fonzie, a show-stealer who quickly became a fan favorite, and America watched him and the Winslow children grow up over the course of nearly a decade.
Matters spent its first 8 seasons on ABC, where it had spun off from Perfect Strangers. Harriette Winslow debuted on that show as an elevator operator, and now we'd meet the rest of her family, including husband Carl (Reginald VelJohnson, "Die Hard"), a Chicago cop; son Eddie (Darius McCrary), and daughter Laura (Kellie Williams). Once Urkel was established as a regular, a steady subplot would find Urkel pining for---and eventually winning the love of---Laura. During the series, Urkel created a transformation chamber that would allow him to morph, "Nutty Professor"-style, into the suave, handsome Stefan Urquelle, believing that was what Laura wanted all along.
Somewhere along the way, the writers turned Stefan into a completely separate entity who was phased out during the final season, when the series shifted from ABC to CBS, along with stablemate Step By Step. In the series finale, Steve became an astronaut, and, if memory serves, he & Laura became engaged.
In season 8, the final ABC season, Urkel found another means to use the transformation chamber, as a street gang, the Piranhas, found out to their sorrow. Jason David Frank (Mighty Morphin Power Rangers) guest stars, and likely also choreographed the fight scene.
Post-Matters, Orlando Brown (3J) would resurface at Disney (That's So Raven), and Jaleel White, currently doing a car commercial trading off his famous alter-ego, shed his Urkel image in a series of roles, including hosting a reality game for SyFy, Total Blackout, which lasted two seasons.