The Gundam Series (ガンダムシリーズ Gandamu Shirīzu?) is a metaseries of anime created by Sunrise studios that features giant robots (or "mecha") called "Mobile Suits" (MS); usually the protagonist's MS will carry the name Gundam.
The metaseries started on April 7, 1979, as a serial TV show called Mobile Suit Gundam. That first TV series has since spawned a franchise that has come to include works released in numerous media. Titles have appeared in the form of multiple television series and OVAs, movies, manga, novels and video games, among other modes. The story from the original 1979 series has been considerably extended with sequels, prequels, side stories and alternate timelines. As a result, the title Gundam has become a collective term for the seven distinct but related timelines that can be pieced together from the stories that appear in the Gundam franchise. Generally speaking, the timelines do not intersect, but they do contain a few common elements such as the titular war machines called Gundam. However, all Gundam timelines and worlds, long after their own anime series, do eventually intersect and combine in the series Turn A Gundam.
Exoskeletons for soldiers count as "giant" now?