A computer processor, the CPU is very fast and continuously reads data from memory. The data from the system memory is often unable to keep up with the CPU speed and the processor has to wait for the data to arrive. To solve this problem, there are high-speed memories in the CPU, called the cache. The cache memory is the high-speed memory in which the data for the currently running program is stored temporarily.
When you start receiving a CDN service, the CDN network copies static content from your site to its own servers and transmits this content to its servers. Thus, the static content from the nearest location to the user is transmitted more quickly to the user. Considering the fact that static content is mostly image, audio and video content (the content that takes up the most space), it is possible to observe a significant increase in the speed of the website opening.
Web Cache Systems – CDN