What is a show reel? Well, simply put a show reel is a collection of small videos put together into a bigger video which cuts or jumps between each of the smaller videos. A showreel is used by performers to showcase their work.
I'll quickly mention that 'show reel' is also sometimes written as 'showreel'. Neither one is incorrect.
I'll use an actor as an example. An actor’s showreel would be a collection of different scenes that the actor has been in from films or TV series. Actors will sometimes create scenes specifically for their show reels.
The basic purpose of a showreel is to showcase different skills the actor has, as well as different works the actor has been. Sometimes there is a type of role the actor could play, but they haven’t portrayed that role in a film or TV series yet. This is why they will sometimes create scenes for the show reel in order to showcase that role.
Another example of who could use a showreel is a dancer. Similar to an actor, a dancer’s showreel can be a collection of videos from live performances or videos of dances put together in order to showcase different styles of dance or different dance skills and techniques.
A musician could have a video of live performances or working in studios.
You may sometimes hear a showreel referred to as a demo reel. A lot of people use them interchangeably, although technically there is a difference between the two terms. How they're made and what they're used for is the same, but a demo reel usually refers to more technical work. It's all creative work, but a demo is more the technical work as opposed to the performance work. For instance, actors, musicians, dancers, will all use show reels, while on the other side as a filmmaker, a director, a camera operator, or a photographer showing behind the scenes, they use demo reels.
A show reel ‘shows’ the performance, while a demo reel ‘demonstrates’ the technical work.
Here's an early example of my director's demo-reel: