Looks kind of simple to me at first glance...

There are four properties in an accessibility tree object:

name

How can we refer to this thing? For instance, a link with the text "Read more" will have "Read more" as its name (find more on how names are computed in the Accessible Name and Description Computation spec).

description

How do we describe this thing, if we want to provide more description beyond the name? The description of a table could explain what kind of information the table contains.

role

What kind of thing is it? For example, is it a button, a nav bar, or a list of items?

state

Does it have a state? Examples include checked or unchecked checkbox states and collapsed or expanded states for the element.

https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree