# Microsoft Graphics Device Interface GDI is a Microsoft Windows graphics and device-output subsystem. ## Source - [[Scanned_20260730-1806#Page 6 — `Scanned_20260730-1806.pdf`, PDF page 6|Scanned_20260730-1806, PDF page 6]] The notebook places it near raster-image wording, but GDI is a subsystem rather than a file extension.