All in one SEO pack & Google XML sitemap

Is there any difference in these two plugins?

– All In One SEO Pack

and

– Google XML Sitemap

I apologize for my ignorance on this. I am self teaching myself on these and just learning. Is there a difference in the two? If not should I have one vs the other? Should I have both? Is there any other plugins I should have to get better search results from Google, Yahoo, and Bing? I created a website for my online business and looking to get the best search results.

Thank you….

Jason