The slightly longer version 🙂 :
The Browser shows you the Images contained in any selected container(s).
You can sort the Images in the Browser ascending or descending, on _any_ metadata field you can show in List View.
List View is one of the two ways of displaying Images and data in the Browser. The other is Grid View. There are buttons on the top right border of the Browser to switch between List and Grid views (also "View→Browser (the second "Browser" in this menu)→{List} or {Grid}").
The metadata in List View is shown as columns. Clicking an already-selected column header toggles ascending/descending (just like in Finder). You determine which columns show by checking them in the "Browser & Viewer Metadata Overlay" dialog box (button on bottom right of Browser border, also "View→Metadata Display→Customize"; NB: not on the "Metadata" menu, on the "View" menu).
There are two Metadata Overlays for List View: Basic and Expanded. I suggest adding _every available metadata field_ to the "Expanded" Overlay set. This will give you a spreadsheet-like table showing you all the Images in the selected container(s) and all the available metadata. Click a metadata column header to sort on that column's metadata. When you change back to Grid View this sort order is maintained, and will show in the drop-down sort order control in the top left of the Browser border.