What are HTTP requests?
HTTP requests are requests that get sent to the server whenever someone visits your website. These requests can contain a variety of information for the server to process and act upon. The most important part of such a request is the URL. Based on this information, the server will try to return a valid response, such as a file. The first stable implementation of HTTP, HTTP/1.0, does these requests in series. This means that a group of requests needs to be finished before the next group is sent. Obviously, this means that pages with a lot of external files will suffer from longer loading times, making your website slow.
Reduce the number of files
Another option to speed up your website is by limiting the number of files that load. This is because for every file you try to load, your browser sends a separate HTTP request to the server. Fewer files mean fewer requests and therefore a faster website.