OpenCV (Open Source Computer Vision Library: http://opencv.org) is an open-source BSD-licensed library that includes several hundreds of computer vision algorithms.
Computer vision- It is an inter disciplinary field that deals with how computers can be made to gain high level understanding from digital images or videos.
Images and Videos
OpenCV reads images in form of matrices
These are matrices consisting of elements that represents intensity of images
color image- 3D matrix – length,breadth,channels where channels is equal to 3(Red,Green,Blue)
Black and white- 2D matrix – length,breadth,channels where channels is equal to 1(Black) so it is a 2D matrix
Multiple images or frames that are displayed very quickly so it looks like a video.