Specifications  of  Projectors :

Brightness: Measured in Lumens

Resolutions: Number of pixels in a unit.

SVGA, XGA, WXGA, UXGA, HD, 4K

Throw Ratio: Eg 1 to 1.25 

Contrast Ratio: Ratio of black to white colors

Native Aspect Ratio: Length to Breadth ratio

4:3, 16:9, 16:10, depending on the content Image projected

Image size: Minimum to Maximum Image size, e.g.,30″ to 300″ Diagonal

Keystone correction: Vertical and Horizontal correction of Image

Light Source: Lamp, LED or Laser

Lamp life or Light source life is measured in expected in Hours