The ICO file format is an image file format for computer icons in Microsoft Windows. ICO files contain one or more small images at multiple sizes and color depths, such that they may be scaled appropriately. In Windows, all executables that display an icon to the user, on the desktop, in the Start Menu, or in Windows Explorer, must carry the icon in ICO format. Icons introduced in Windows 1.0 were 32×32 pixels in size and were monochrome. Support for 16 colours was introduced in Windows 3.0, while Windows 95 introduced 24-bit RGB colorspace and several larger dimensions (64x64, 128x128, etc.)
Simple graphic format in color. Use 24 bits per pixel: 8 for red, 8 for green, 8 for blue if the maximum gray value is 255, uses 16 bits for red, 16 for green and 16 for blue if the value is greater than 255 and less than 65536. a PPM file is plain text and can be modified with a single processor, there is also not readable binary version of word processing normally. It is related to the PGM (grayscale) and PBM formats (black and white).