In-stream video is a type of advertising format that is used to deliver video ads within digital video content. In-stream video ads are typically shown before, during, or after a video, and are designed to be watched by the viewer along with the video content. In-stream video ads can be effective for advertisers, as they can provide a high-quality and engaging experience for the viewer, and can be targeted to specific audiences based on their interests or behaviors. In-stream video ads are also beneficial for publishers, as they can provide an additional source of revenue, and can help to increase the engagement and retention of their audience. In-stream video ads are typically delivered through video ad networks or exchanges, and can be measured and tracked using a variety of metrics, such as viewability, completion rate, or engagement.