Are photos gathered in albums in full or partial resolution?

The photos are stored only once in the library, in the full resolution. Standard albums are referencing the stored photos, so you are seeing them in the albums also in the full resolution, with all metadata.

Shared albums are not like the standard albums at all. Shared albums are storing their own versions, optimized for sharing, scaled down to 2048 pixel at the longest edge and many metadata will be stripped, so we are not accidentally sharing more information than intended.

TenThousandThings wrote: Are photos gathered in albums in full or partial resolution?

Pictures aren't exactly "in" an album. When you put a picture into an album, its name is added to a list of pictures to display when the album is clicked. So two albums can both have the same picture name in their lists, and that picture will show up when you click either album. And when you delete a picture from an album, its name is removed from that album's list, but its name remains in the lists of other albums. 

So albums give a specific collection of your pictures. My Grand Canyon album, for instance, offers a collection of pictures taken on various trips to the Grand Canyon, and my Trip to California album shows the pictures on that trip, some of which are the same pictures as shown in the Grand Canyon album. 

But there is only one, full resolution, copy of each picture. That same picture is seen in each album with that has its name in the album's list.

And the Library View shows all of the pictures in the entire Library. You can't remove a picture from the Library View without deleting it entirely. So Library View is not like an album at all.