Image search engines are online tools that allow users to find pictures based on keywords or uploaded images. They work by scanning the internet for images and indexing them, making it easy to retrieve relevant visuals. Popular examples include Google Images and Bing Images. When a user enters a search term, the engine displays a grid of images that match the query. Users can click on these images to view them in larger sizes or visit the original websites. Image search engines are useful for finding inspiration, identifying objects, or gathering visual information for various projects.