Group
The predecessor to the computer applications for making presentations was a series of photographic slides in a slide tray. When assembled into a presentation, the collection of slides was called a 'deck', as in a deck of cards. The term is probably just a holdover term.
A transformation that slides a figure horizontally is called a translation. A transformation that slides a figure vertically is also called a translation.
The four small slides are called thumbnails. These slides are shown in the different slide view options in Microsoft PowerPoint.
slides
They are called slides. They do not have another name.
Megagon
thumbnails
A translation.
At collection of stamps is refered to as a stamp collection. They are frequently kept in albums. Philately is the name for the study and collection of stamps.
it is called a range of mountains
a collection of fish is called a school of fish
A collection of fish is called a school.