An image viewer is a software application designed to display digital images. It allows users to open, view, and sometimes edit image files in various formats, such as JPEG, PNG, and GIF. Image viewers often provide basic features like zooming, rotating, and slideshow options, making it easy to browse through collections of pictures. Many image viewers are included with operating systems, such as Windows Photo Viewer for Windows or Preview for macOS. There are also third-party options available, like IrfanView and XnView, which offer additional functionalities, including batch processing and advanced editing tools.