Liz Parker is portrayed as a typical girl next to door, at least from the outside. She is beautiful though she doesn't really realize it. She is smart and very direct about her opinions, sensible, confident and levelheaded. Her home was above the diner her family owns, the Crashdown Café, and until the last episode, she worked there as a waitress after school. She did well in school, especially in science that had been her passion since she was a child. Her dream was to go into molecular biology at Harvard University. However, after the events in the season three finale, Liz's whereabouts are unknown.

Liz is a complex character; very sweet and kind overall, yet strong and determined. Control is something very important for her: with it, she can get facts and answers and this makes her feel more safe about herself, those she loves, and life in general. However, her real nature isn't really so controlled. When Max saves her life and she falls in love with him, everything in her life changes; Max is the living proof that people cannot control everything and even science doesn't have all the answers. She understands this, and realizes that she has to follow her heart and live in the moment, because no matter how people try, they can't control everything and they can't choose with whom they fall in love.
Liz emerges as the "brain" among the group. She is the one who continuously gets the very core point of their problems and is able to find a solution most of the time - especially if the problem is science related. However, her determination and selfless spirit mixed with her sometimes controlling nature can also be a character flaw when it leads her into making decisions where she takes too much of the responsibility. This is also a characteristic that she shares with Max Evans.
It is stated that she loves White Roses in the season 2 episode, End of the World.