Single Sliding Window

• Single sliders have two separate window sashes, but only one is operational. The operational sash slides past the stationary sash to open and allow fresh air. With a single slider, a screen is provided to cover the operational sash area, but not the stationary sash.
  
  

Double Sliding Window

• With double sliders, both sashes operate and slide past each other. Typically, each sash opens less (about half as much) as a single slider would. You achieve the same amount of opening by opening both sashes to their max but the open area is on either side of the window. These windows are sometimes chosen for larger applications.
  
  

Atrium Sliding Windows

• An atrium slider is a window that has a fixed sash in the center with a sliding sash on either side. The sliding sashes slide over the fixed sash when opened. These windows are often designed so that the fixed sash is twice as large as either sliding sash, but can also be made so that it is the same size.
  
  

Single- and Double-Hung Windows

• Technically speaking, single- and double-hung windows are also sliders, though they slide up and down rather than horizontally. With a single-hung window, the top half is stationary and the bottom sash opens. Double-hung windows have two operating sashes that can slide past each other. These windows require balancers to hold their weight in the open position.