Copy-move forgery detection is one of the most popular image forgery technique in which a part of a digital image is copied and pasted to another part in the same image with the intension to make an object “disappear” from the image by covering it with a small block copied from another part of the same image. Hence, the main task of copy-move forgery detection is to detect image areas that are same or almost similar within an image. These method in general use two approaches namely key-point based and block based. This paper provides a review of copy move forgery detection on various techniques. Keywords: Copy move forgery, Lexicographical Sorting, Digital Image Forgery, Duplicated Region.