A window blind is a type of window covering. There are many different kinds of window blinds which use a variety of control systems. A typical window blind is made up of several long horizontal or vertical slats of various types of fabric, wood, plastic or metal which are held together by cords that run through the blind slats. Window blinds can be adjusted by rotating them from an open position to a closed position with either a manual or remote control which allows the slats to overlap and block out most of the light. There are also several types of window blinds that use a single piece of material instead of slats.
A window blind is also known as a window shade.
The term window blinds is also sometimes used to describe window coverings generically—in this context window blinds include almost every type of window covering, i.e. shutters, roller blinds, honeycomb shades, wood blinds, roman blinds and of course, standard vertical and horizontal blinds. Sometimes called blinds or shades.
Source: http://en.wikipedia.org/wiki/Window_blind