Steganography is the art of hiding the fact that communication is taking place, by hiding information in other information. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the Internet. For hiding secret information in images, there exists a large variety of steganographic techniques some are more complex than others and all of them have respective strong and weak points. Different applications have different requirements of the steganography technique used. For example, some applications may require absolute invisibility of the secret information, while others require a larger secret message to be hidden.. This paper in tends to give an overview of image steganography, its use sand techniques. It also attempts to identify the requirements of a good steganographical go rithmand briefly reflectson which steganographic techniques are more suitable for which applications