if your website has to face the whole world, you have to think of the loading time of each page in your website.
if your website is just plain text format with little graphics, it is ok to just host on one server.
However, if your website involve heavy graphics, videos or even flash, some regions would have loading issue on your website.
Most likely cloud hosting actually can solve your problem, but if you have limited budget, you have no choice.
CDN stands for Content delivery network, it is much similar to cloud hosting, they call it CDN nodes.
what you have to do is to change all images pointing to a sub-domain, like http://cdn.yourdomain.com.
CDN nodes are placed on different locations, visitors may get the graphics, videos from the nearest CDN node.
There are different pricing plans, some are in monthly basis, some are in bandwidth usage basis, for eaxmple 1TB per year.
There are lots of CDN providers, just google it and you could find some.