These blinds can be classified broadly into 5 different categories, the Venetian blinds, the Roller blinds, the Roman blinds, the Pleated blinds and the Vertical blinds.
Many window blinds are made with slats of fabric, wood, plastic, or metal that adjust by rotating from an open position to a closed position by allowing slats to overlap. A roller blind does not have slats but consists of a single piece of material. Metal window blinds are often used outside of the home or business to protect against theft, temperature, vision, bad weather, and fire (in fire-prone areas). Often these blinds are machine-operated, rather than hand-operated.
The horizontal version uses a thin woven corded "ladder" system to suspend the slats and enable slats to be closed via a rotating drum to which each upper end of the woven ladder is wrapped and attached. A lift cord allows the blind to be pulled up and stack tightly to top of the window when desired. One of the earliest patents for a window shade was in 1888 by George L. Castner.
The vertical version uses a generally wider slat and has the added feature of being able to pull a cord to stack the slats together either to one side or to separate in the centre and stack on each end. This vertical blind allows rotation of slats by a rotating shaft in the upper head rail housing which runs through independent geared carriers that will convert twisting of tilt rail to a rotation of each individual slat in synchrony. The original vertical blinds were invented in Kansas City, Missouri by Edward Bopp and Fredrick Bopp who held the original patent. The company name at the time was Sun Vertical. In the 1960s, the patent and company was sold.