For many of us, there doesn't seem to be a difference between an autobiography and a memoir. But, as most publishers would agree, there is a difference, albeit a subtle one. The basics are the same: Both an autobiography and a memoir are written about a person by himself or herself (occasionally with the help of others).
So, what's different? It's the actual content. Generally speaking, an autobiography is all-encompassing, spanning the entirety of the subject's life from birth up to the time of writing. The story line, most often, unfolds in a linear and even-handed fashion, covering most of the major events along the way. Less often, the story meanders back and forth through time, touching on a hodgepodge of topics the subject sees fit to discuss.
A memoir, however, is usually focused on a particular portion of a person's life or a specific theme. In some instances, the events may span the entire course of the subject's life, but they are conveyed in relation to some focal point. A presidential memoir, then, is either a snapshot or a full view of a president's life as it relates to his presidency.
Now, let's take closer look at presidential publishing.