YouTube offers several ad formats, such as skippable and non-skippable in-stream ads, discovery ads, bumper ads, and video discovery ads. Each format has its own advantages and disadvantages, depending on your goals, budget, and audience. For example, skippable ads allow users to skip after five seconds, which can reduce your cost per view, but also lower your engagement and retention. Non-skippable ads ensure that users watch your entire message, but they can also annoy them and increase your bounce rate. Discovery ads appear on the YouTube homepage, search results, and watch page, and can drive more organic views, but they require a compelling thumbnail and headline to stand out. Bumper ads are short, six-second ads that play before or after a video, and can increase your brand awareness and reach, but they limit your creative options and message. Video discovery ads are similar to discovery ads, but they only show on the watch page, and can generate more qualified leads, but they also have lower click-through rates and impressions. To choose the right ad format, you need to consider your campaign objectives, budget, audience, and creative assets, and test different options to see what works best for you.