Difference between diferent video related Adsense product

AdSense for video
AdSense for video allows publishers with video content to earn revenue using relevant, non-intrusive ad placements from Google's extensive advertiser network. Video content will display both InVideo overlay and text overlay ads.

At this time, AdSense for video is in Beta may only be implemented for pages and videos that are in English with traffic primarily from the United States. If you're interested in participating, learn about the requirements, then fill out our interest form.

Adsense video ads
Click-to-play video ads are a new type of ad available for sites in the Google network, including AdSense sites. They're available in several ad formats and will be shown only if a publisher is opted in to image ads for one of the supported ad formats.

When a video ad is served to a page, it will be displayed as a static opening image. Once the user clicks the play button or the opening image, the video will begin playing within the ad space. If the user clicks the display URL at the bottom of the ad, or clicks the ad while it's playing, the user will automatically be taken to the advertiser's website. Users can control the volume and can replay the video if they choose; the video will not automatically replay.

Adsense Video units
Video units are a new way to enrich your site content -- and earn more -- with relevant video from YouTube partners on an embedded, customizable video player. When you place a video unit on your site, you can choose the video content in several ways: by picking content categories, by select individual content providers, or by having video automatically targeted to your site content.

The videos you display will be monetized with relevant ads, too. The video unit displays companion and text overlay ads that are highly targeted and non-intrusive. Plus, to help integrate video units into your site further, you can also customize the color scheme and layout of the video unit.