Watch hours
Watch hours are the total time viewers spend watching a YouTube channel's public videos, a monetisation metric counted in hours of playback rather than in number of views.
A view counts once however long it lasts, while watch time accumulates minute by minute. One view that plays a video for 30 minutes adds half an hour; 60 views that each leave after one minute add one hour between them. That is why watch hour services are priced and measured differently from view services. The platform decides which playback counts toward its requirements, over what period and on which videos, so check its current rules rather than a service description.
Mechanically, a watch hour order means long playback on long videos. Service descriptions often require a minimum video length, because a short video cannot produce many hours per view, and some ask for one long video while others spread delivery across several. The quantity is in hours, so a rate per 1000 is a price per 1,000 hours. The panel cannot read your watch time, which appears only in your own channel analytics, so start counts and disputes are settled on screenshots you provide or on view counts, depending on the panel.
Two things cost buyers here. Analytics can report watch time with a delay, so an order marked completed may not show its hours for some time, and a complaint or refill request made too early compares the wrong numbers. And because the platform decides what qualifies, hours that appear in analytics can later be revised or discounted. A panel can deliver playback; it cannot promise how the platform will count it.
What it does not mean
Watch hours are not views, and a large view count does not imply many watch hours. Buying views on a short video adds little watch time, and buying watch hours does not by itself make a channel eligible for anything, since eligibility depends on other conditions the platform sets.