I have been seeing that a new way of exploiting ignorant people on the web now is through what they call CDN, content delivery network. It is like the new thing now, and i know that means another stream of revenue for the web hosting companies if they decide to join soon as i predict ( http://mediatemple.net/labs/cdn/ ) Anyways if you know how exactly this CDN works please contribute on this thread. I don't know much about it as i am trying to learn but to my knowledge i think if one have a nice server with nice bandwidth and great cache from RAM, one wouldn't be so much dependent on this CDN fraud. Fr example if one has a 4GB RAM, and like 10TB 100mbps bandwidth, of what use does the CDN be? I understand with different servers spread all over the CDN will still offer some speed but would one need any speed especially for like just image hosting. Even videos, the specs i gave should be enough to make your website fast. But i guess they know alot of people will not understand what the CDN really means and they can exploit their ignorance by claiming speed. Please share your knowledge. Thanks!!!
CDN stores all your static files (eg. images) and distribute it across different various locations. I will explain to you in a real life scenario. There will be minor configuration (CNAME, etc..) to be done. If a user post a thread and upload images into the forum, the images will be stored in webhost server (US server) itself. CDN will cache the images and distributed it across their servers and locations. When the user visit the thread, for eg. a UK visitor, the CDN will load the images from CDN UK server instead of the webhost server. This achieve some significant advantages. 1) It reduces CPU/Memory load on the US server as the CDN serve its images from their own servers. Most sites are loaded with images, and this will certainly bring a hugh advantage of loading speed and reduce CPU/Memory resources on the webhost server. 2) Faster latency. As the images loaded are nearer to your visitor via the CDN, the images will be loaded fast. 3) If one of their servers is down, there will be another server to load up the images to your visitors. I hope this will be clear to you, pm me if you are still in doubts, I will do my best to explain to you.
The thread created by the US user will not be instant visible to the UK people. It will take few minutes to visible to all global user.
Well How relevant it is. If a person start a thread and and first will it be loaded to USA server and from there only static part move to other servers around the world. So initially no difference how fast a person accessing a USA server with or without CDN from UK. But in later time the speed will increase after the caching is done but then given the latest servers and bandwidth there won't be much difference in speed it will be a difference in micro seconds. The real thing will be server load. That we need analysis with price of CDN with up gradation of webhost in USA itself