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.
It is a lossy format, which means that when the image is compressed, some of the image data becomes lost. JPEG is ideal for displaying images on the web because it dramatically reduces the file size of the image without significantly reducing the quality.PEG format is best for photographs or other images with a smooth, gradual shading. JPEG images not only help to save space on servers, they also reduce bandwidth and download times. The reduction in size of the compressed image is usually significant, even with minimal compression.