The Bing Image Search API returns a list of relevant images from a search query which include thumbnails, full image URLs, publishing website information, and image metadata. Also, it offers several filters such as image type, layout, freshness, and license. This API provides a list of images similar to the "Bing.com/Images" site, but the experience is not exact. Currently, a free plan that limits calls to 1000 transactions per month is available. The Image Search API uses JSON format for data exchange, and API Keys for authentication.