Estragon and Vladimir, or Gogo and Didi, are the two protagonists of this play. They live out their life waiting for man named Godot, believing that Godot will come to them. A boy comes at the end of each day and announces that Godot is not coming, but will come soon. They continue to wait. The two both have names of seven letters, and both have two syllable repeating nicknames - Beckett is calling attention to their connection.
The way their clothing is described suggests that these two characters, who are only shown on a roadside waiting, may have been gentlemen of financial means at some point. They have on jackets and boots of a respectable nature. They are now homeless, though, as evident in their torn and dirty description.
Vladimir has the better memory of the two, and seems more intelligent. He tries to encourage Estragon to be optimistic, and helps him to pass the time. He is philosophical, and more likely to consider their purpose in being where they are. Estragon is more child-like. He is emotional, and allows himself to be led by Vladimir. He spends quite a bit of time concerned with his feet and his boots, while Vladimir spends a lot of time concerned with his hat. Beckett suggests that these two characters represent the two sides of a human being - Vladimir is the mind (intellect), and Estragon is the body (the emotional/physical).