She is a thin, blonde teenage girl. Her eye color is officially described as blue, though in many shots they appear hazel.
Buffy is a strong willed, bold, brave, and quick witted girl who speaks her mind and stands up for what she believes in. She has superior strength, agility, and even a kind of slayer's sixth sense that allows her to sense vampires. Sometimes this causes her to have dreams that give her knowledge of future or present supernatural events.
Buffy Summers, a retired vampire slayer, moves to Sunnydale with her mother and transfers to Sunnydale High after being expelled for burning down a gymnasium (full of vampires) at her last high school. She immediately befriends Willow and Xander at school, who find out right away after a very close call encounter with some vampires that Buffy is a vampire slayer. They become her best friends who support her and help her through her supernatural trials throughout the series. She also meets the new school librarian Rupert Giles who is assigned to be her "watcher" or in other words her guide and advisor to all things supernatural. He also quickly becomes her dear friend, a relationship that sometimes even resembles a father figure. She comes to Sunnydale sick of vampire slaying because it has cost her to give up her school, friends, and to pick up and move her entire life before. She wants to put her messy past behind her, however, the universe has other plans for her. Buffy moved to Sunnydale in the midst of preparation for the Harvest, in which vampires will offer humans to The Master, who is trying to open the Hellmouth, a supernatural portal which Sunnydale High sits atop. He plans to exterminate humans and have vampires control and roam the Earth instead. Thrown in the middle of mystical mayhem, Buffy is forced to use the skills that come with being chosen by the universe as the one slayer of your generation to save her friends and fight the evil that has come to town. This sets the tone for the rest of the series, as she and her close friends fight off evil time and time again.