Actually, it is close by

So a copy is kept close by

But most of the videos people watch a lot never cross the sea. The video company puts its own servers inside Korean telecom buildings and copies popular videos there in advance. Then the request gets its answer right at the telecom building. It takes only about 0.01 seconds, about one tenth of the trip across the sea.

Why?You do not go to the factory every time you want a snack. Popular things are stocked at the corner store ahead of time. The internet works the same way. Keeping popular videos close makes them faster, and the undersea cables are less crowded.

Learn moreA copy kept nearby is called a "cache," and this way of storing copies close to people is called a "content delivery network (CDN)." New videos, videos few people watch, and small websites across the sea still cross the ocean.

Time

118 ms → 129 ms

Simplified route · light in glass at about 200,000 km per second