Saitama is a neighbor prefecture of Tokyo, so that there are a lot of people who lives in Saitama and commuting to Tokyo. The capital is Saitama city (さいたま).
If you are into Japanese anime, you might know the name of this prefecture from Crayon Shin-chan (クレヨンしんちゃん), a story of a Japanese family which has a son of 5 years old. His house is located in Saitama prefecture, and they talk about the feature of the prefecture so often within the story.
Many people say that Saitama is a place where people own their house and there is not so much to see, however, there are some attractive places, and you can even make it a short-day trip from Tokyo.