Photoshop Document (.psd)
The PSD file extension stands for Photoshop Document, which is the native file format for Adobe Photoshop. It is primarily used to save graphics and images, preserving layers, masks, transparency, and other editing features, allowing for non-destructive editing. Introduced in 1988 with Photoshop's first release, PSD files have since become a standard in the graphic design and digital imaging industry due to their flexibility and support for various color modes and channels, including RGB, CMYK, and grayscale.