Apps :: Auto App Updates In Store

How do auto updates work in the store? I noticed when I went into it there were some updates showing for things like calculator and one note. The progress bar indicated they were fully downloaded but they didn't seem to be disappearing from the list or installing themselves. Is this normal behaviour? It's not an issue as I clicked the download arrow and this seemed to manually prompt their installation immediately. They all worked fine.

i guess what I am asking is would they of installed eventually on their own? I only had the computer on for about twenty minutes or so. It didn't have loads of time to do its thing perhaps. Maybe they download and install themselves after a certain period of idle time? Or on shutdown? How often does the store to app update checks - are they pushed or is there something like once in every 24 hours in place? do recall spotting this once before with some of the MS core apps.