A miter saw is a type of stationary saw designed to make precision cuts at multiple angles. The blade is pulled downwards onto the material, unlike with a circular saw where it feeds through the material.
Miter saws are best for cutting longer boards thanks to their large cutting capacities. Typical applications of a miter saw include making quick and accurate miter cuts (such as at 45 degree angles for making picture frames) or for making cross cuts for molding.

Types of Miter Saws and Their Uses
There is a huge range of miter saws available on the market. Single bevel, double bevel, sliding, compound etc. I have summarized each type below.
Single bevel – Can make miter cuts and bevel cuts in a single direction.
Double bevel – Can make bevel cuts in both directions. Double bevel mitre saws are better for when you need to make multiple angled cuts as they save time on switching the direction of material.
Compound miter saw – Allows you to make compound cuts (when you make a miter cut and a bevel cut at the same time).
Sliding miter saw – This type of miter saw slides on a bar to allow the blade to move forward instead of just straight down. They are capable of cutting wider boards than non-sliding models.
