Why does the word autobiography mean a self written account of persons life story?

The word "autobiography" is derived from three Greek roots: "auto," meaning "self," "bio," meaning "life," and "graphein," meaning "to write." When these roots are combined, the word "autobiography" literally translates to "self-written life story." This term accurately describes the genre of writing in which an individual writes their own account of their own life, providing a firsthand and personal perspective on their experiences, thoughts, and feelings.