PGM is a document format: it stores data in the PGM format. ICO is a image format that bundles multiple raster images at different resolutions (16x16 through 256x256) into a single file for use as application icons. This renders each page as a raster image, making the content viewable without a document reader. Each page is rendered at the specified DPI and saved as a separate image; text in the output is no longer selectable. Converting between these two formats is common when the source application does not support ICO natively or when the target platform only accepts ICO. 1converter processes this conversion server-side using open-source tools. Files are transferred over HTTPS, converted on secure cloud servers, and automatically deleted after 24 hours.