Star Trek: The Original Series is a revised title for the series Star Trek, which originally aired as a TV series on NBC from 1966 to 1969. The series began the Star Trek franchise and has gone on to have stories in multiple formats; novels, comics, short stories and video games.
The sub-title The Original Series is used to distinguish it from its sequel series, and from the larger Star Trek franchise. The sub-title is used on some products, such as DVDs, however novels and comics continue to title TOS publications simply as Star Trek.
Star Trek the TV series, and many of the subsequent stories, chronicled the voyages of the starship Enterprise, under the command of Captain James T. Kirk on its five-year mission of exploration through the Alpha and Beta Quadrants in the late 2260s. The series later spawned a movie-series, which, along with fiction in other formats, continued the adventures of Kirk and his crew through to the end of the 23rd century and onto a new ship; the Enterprise-A.