Server Caching and CDN
WordPress caching is the fastest way to improve performance. If your site is getting hit right now install one of the popular caching plugins.
Caching plugins can be easily installed and will cache your WordPress posts and pages as static files. These static files are then served to users, reducing the processing load on the server. This can improve performance several hundred times over for fairly static pages.
The most popular WordPress plugin for Server Caching (including Browser Caching) is WP Super Cache.
For more information on how to speed up your site using third-party plugins and site speed report tools please check the following documentation link.
CDN (Content Delivery Networks)
A content delivery network (CDN) is a system of distributed servers (network) that deliver pages and other Web content to a user, based on the geographic locations of the user, the origin of the webpage and the content delivery server.
This service is effective in speeding the delivery of content of websites with high traffic and websites that have global reach. The closer the CDN server is to the user geographically, the faster the content will be delivered to the user.
CDNs are not for everyone, they should be seen as the final option for really optimizing your site. It depends on your budget and needs, if all the other options haven’t helped then a CDN will do the trick, especially if serving a large base of international clients. The following 2 are viable and affordable solutions for photographers’ needs:
MaxCDN – pricing starts at $9 a month for 2 sites, for up to 100GB bandwidth. Their solution is great for most small to medium website owners, and is easy to implement. MaxCDN is a popular and well-known CDN that powers the likes of The Next Web, Garmin, Kodak and WP Engine.
Cloudfare – Offering a free basic plan Cloudfare is useful for testing out a CDN and improving speed. Paid packages start from $20 per site. Unlike many CDNs, CloudFlare doesn’t charge for bandwidth usage. On the basis that if your site suddenly gets popular or suffers an attack, you shouldn’t accumulate a huge bandwidth bill. According to CloudFlare, on average a website using the CDN will load twice as fast, use 60 % less bandwidth, have 65 % fewer requests, and is more secure. Used by Reddit, Zendesk and MIT.
For more info please consult this documentation link.