The word canopy can mean different things. There are several different types of people who use canopies as well. The canopy can mean anything from a forest roof to an aircraft top. You can have a glass canopy or a flexible one made of vinyl or canvas.
The aircraft canopy is the clear glass or plexiglass portion of the cockpit. This is what the pilot sees out of and what he or she opens to get into the plain. You can see this type of canopy mostly on fighter planes and the smaller cargo planes. Commercial jetliners do not have a canopy. They have a cockpit and windows instead.
Forests also have a canopy. This is the name for the covering of trees that shade the ground in large forests. The rain forest canopy is often talked about because of the amount of life it houses. Every forest has a canopy that shades it. This type of outdoor canopy is used by the forest inhabitants for protection and sometimes living space.
There are also wooden and glass canopies for things like gazebos and small outdoor structures. These are often made from a variety of materials. This type is used by people where ever the canopy happens to be. They can be used for everything from a shady place to sit and read to a place to hold a back yard barbecue.
Some of the canopy gazebos are wooden permanent structures and some are vinyl or open air structures that are just for shade. These types are used year round depending on the weather. They can also be used to house things.
No matter what type of canopies you are talking about you are likely to encounter a variety of them. They come in all shapes and sizes as well as all materials. Some of them are natural formations while others are man made.