The first digit assigned to all Visa cards is four, and the second through sixth numbers are connected to the financial institution. Then, either the seventh through 12th numbers, or the seventh through 15th, are the account number, while that final 13th or 16th digit is the check number.
Limited color, Lossy format, small file. GIF(Graphics Interchange Format) is limited to an 8-bit palette, or 256 colors. This makes the GIF format suitable for storing graphics with relatively few colors such as simple diagrams, shapes, logos and cartoon style images.
Joint Photographic Experts Group jpg. JPG, also known as JPEG, is a file format that can contain image with 10:1 to 20:1 lossy image compression technique. With the compression technique it can reduce the image size without losing the image quality. So it is widely used in web publishing to reduce the image size maintaining the image quality.