Digital watermarking is the processing of combined information into a digital signal. A watermark is a secondary image, which is overlaid on the host image, and provides a means of protecting the image. In order to provide high quality watermarked image, the watermarked image should be imperceptible. This paper presents different techniques of digital image watermarking based on spatial & frequency domain, which shows that spatial domain technique provides security & successful recovery of watermark image and higher PSNR value compared to frequency domain.