Sonata-allegro form typically consists of three main sections- an exposition, a development, and a recapitulation. The exposition introduces the main themes of the movement, the development explores and develops these themes, and the recapitulation restates the themes in their original keys.
In contrast, binary form consists of two main sections, an exposition and a reprise, which is essentially a repeat of the exposition. There is no develpment section in binary from.