How do Samsung apps get updated on Samsung devices? Many of the Samsung apps, such as the Camera are not available on the Google Play Store.

What mechanism is used to update these apps?

Is it "Samsung Push", "Galaxy Apps", or something else entirely?

(Samsung's "Galaxy Apps" is unbelievably permissions-intensive and also requires the user agree to a long "Terms and Conditions" agreement before using it.)
Some are updated by a system OTA. Some others are either OTA-ed, or updated via Play Store. In total, they are updated in a moxed way of system OTAs and Play Store.

To be simple: Whatever you can find on the Play Store is updated via PS, and whatever else is shipped with an OTA.

I'm never a Samsung user but my friend has a Samsung, so I can only tell some of them (i.e. this list is incomplete):


Samsung Push Service
Samsung Browser
...And a built-in QR scanner (I forgot its name)