These are the fields used internally by Joomla!. Let me explain what everything does:

• Status: is it enabled or not
• Update site: The name of the update site
• Name: The name of the extension being updated (this is fetched from the #__extensions table using the extension ID stored in the update site definition)
• Location: This is mainly used for templates and modules. It tells you if it's a back-end (Administrator) or front-end (Site) extension. All components and plugins always have Location set to Administrator, otherwise Joomla! won't see their updates at all. So, it's a useful column to debug this kind of update issues.
• Type: The extension type. This is useful because some modules and components may have the same Name and use the same Update Site.
• Folder: This is used for plugins only. It tells you the folder (a.k.a. plugin group) of the plugin. This is useful because many plugins may have the same Name, the same Update Site but exist in different folders.
• Update Site ID needs no explanation, I guess? It's the numeric ID of this update site.

Even though I could only provide the Status, Update Site, Name and Update Site ID in this table I found out that in some cases I was getting what could be perceived as "duplicate entries" when, in fact, it was non-duplicate entries for same-named modules/plugins with the same-named Update Sites. Without the Location, Type and Folder it was impossible to tell them apart, therefore it could lead to someone disabling one or more update sites thinking they are extraneous. This would cause one extension to be updated, the other one not, which would most likely lead to the site being broken.

@brianteeman
Accredited Joomla! Translations is part of every language pack

<updateservers>
        <server type="collection" priority="1" name="Accredited Joomla! Translations">http://update.joomla.org/language/translationlist_3.xml</server>
    </updateservers>

and in the update xmls and cron job to create them automatically on our servers. I am afraid we have to deal with that.
See http://update.joomla.org/language/translationlist_3.xml

OK thanks for the explanation @nikosdion I guess its not that important but I found the site/admin particularly confusing as the languages were listed as site when they are both site and admin.

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/5178.

That’s because of how these packages need to be listed for Joomla! to pick up their updates.=