There are two types of window shutters:
a) those that block all light and air out, provide effective window security and work as either an alternative or supplement to curtaining.
b) those that are pierced, or have slatted louvres (fixed or opening), which allow air and light to pass through. With these types, the air flow can be controlled manually or electronically around the clock and they can again substitute or complement more traditional curtaining.
* Shutters mostly fit close to the windows and open out to the sides – either inwards or outwards depending on the window type and the mechanism used.
* On inward opening casements or sash windows, louvred shutters may be closed over the window opening, allowing the windows themselves to remain fully or partially open.
* As long as shutters are metal or at least solidly made and fitted they can be used temporarily in place of the structural security.
* Flexible louvres protect against rain and against very bright sun, provide privacy while allowing the inner and outer worlds to connect. As windows and doors these are called jalousie.
* Shutters that have louvres for the top half only are called parisiennes.