What is spackling paste used for?

Spackling paste is wonderful stuff if you have a hole in your wall. The paste is made up of gypsum and glue and fits in the hole which will dry. Once dry the spackling can be sanded down and the wall can be painted over. A great spackling job can make it look like there never was a hole in the first place. Spackling is also great for the joint of two pieces of sheetrock to cover it up and make it look like one giant piece. It is worth noting that spackling is used primarily for small repairs whereas joint compound is needed for larger ones. Spackle dries quicker and shrinks less. Joint compound is also called drywall paste.

https://en.wikipedia.org/wiki/Spackling_paste