From Wikipedia:

Star Trek: The Next Generation (sometimes abbreviated to TNG) is a science fiction television series created by Gene Roddenberry as part of the Star Trek franchise. Set in the 24th century, about 70 years after the original Star Trek, the program features a new crew and a new starship Enterprise. It premiered the week of September 28, 1987 to 27 million viewers with the two-hour pilot "Encounter at Far Point". With 178 episodes spread over seven seasons, it ran longer than any other Star Trek series, ending with the finale "All Good Things..." the week of May 23, 1994.

The show gained a considerable following during its run and, like its predecessor, remains popular in syndicated reruns. It was the first of several series (the others being StarTrek: Deep Space Nine, Star Trek: Voyager, and Star Trek: Enterprise) that kept new Star Trek episodes airing until 2005. Star Trek: The Next Generation won 18 Emmy Awards and, in its seventh season, became the first syndicated television show to be nominated for the Emmy for Best Dramatic Series. It was nominated for three Hugo Awards and won two, becoming the first television series since the original Star Trek to be recognized. The first-season episode "The Big Goodbye" also won the Peabody Award for excellence in television programming. The series formed the basis of the seventh through to the tenth Star Trek films.

Klingons are a warrior race in the fictional Star Trek universe. They are recurring villains in the 1960s television show Star Trek: The Original Series, and have appeared in all five spin-off series and seven feature films. Initially intended to be swarthy antagonists for the crew of the USS Enterprise, the Klingons ended up a close ally of humanity and the United Federation of Planets in later television series.