Amazon "stores" refer to physical stores such as Amazon Books, 4 Stars, Fresh, Go, and Popup stores. It does not include the online retail portion of the business. Earlier this year, they announced the closure of almost all of their physical stores to focus on the grocery business. I assume the cuts would be related to corporate employees who support the tech and data behind these stores.

As for "People Experience, and Technology", that is actually one singular organization that includes groups like HR and recruitment. As there are job cuts, they no longer require as many recruiters or HR business partners.

AWS should generally be safe as it is the biggest money maker for Amazon.