This document provides an introduction and overview of digital imaging concepts for a web design course. It covers why images are used, the differences between bitmap and vector graphics, resolution, common file formats, and tips for optimizing images for the web. Bitmap images use pixels and lose quality when resized, while vector images use mathematical formulas and maintain quality at any size. Resolution is measured in ppi, with higher resolution meaning more pixels for clearer images. Common web formats are JPEG, GIF and PNG, while larger original formats like PSD are not recommended. The document concludes with references.