If two sets of hinges it s a tri fold shutter.
Tri fold window shutters.
When referencing number of panels it s for one of the shutters not both i e.
However for wider windows folding shutters can be the better option because of their longer reach.
Some are on tracks while some are not.
Popular for patio or sliding glass doors by pass tracks allow shutter panels to slide past each other on tracks to open and close.
Choosing the right number.
The door style folding shutters are typically on a track but not all folding.
The number of folds refers to the number of shutter panels on each side of the window connected by hinges as opposed to the total number of panels on each window.
The number of folds refers to one side.
Cafe shutters were also popular where the flair fold shutters were only used at the bottom of the window.
Most shutters are single panel meaning they don t have a fold like folding closet doors.
Convenient bi fold and multi fold track for shutters up to a maximum panel width of 20.
So those with a single fold two panels are referred to as bi fold or bi folding window shutters while those with two folds three panels are known as tri fold or tri folding shutters.
If the shutter has one set of hinges it s a bi fold shutter.
The popularity of blinds curtains and drapes decreased the demand for flair fold shutters.
For example if a window has bi fold shutters the entire window will have four shutter panels.
Flair fold shutters were sometimes configured into a double tier unit so it would consist of panels across the top and bottom.
You can also get shutters made up of multiple panels which glide along tracks on a set of wheels pictured.
You can get 2 panel bi fold and 3 panel tri fold types.
Provides even greater panel configuration for larger window areas.