What is the difference between the Statement of Purpose and the Personal History Statement?

The descriptions are listed on the online application and are as follows:
Statement of Purpose:
Please describe your aptitude and motivation for graduate study in your area of specialization, including your preparation for this field of study, your academic plans or research interests in your chosen area of study, and your future career goals. Please be specific about why UC Berkeley would be a good intellectual fit for you.
Personal History Statement:
In an essay, discuss how your personal background informs your decision to pursue a graduate degree. Please include any educational, familial, cultural, economic, or social experiences, challenges, or opportunities relevant to your academic journey; how you might contribute to social or cultural diversity within your chosen field; and/or how you might serve educationally underrepresented segments of society with your degree.