The only three things that matter most to speed up your WordPress website, make it faster are: image optimization, database optimization and enabled caching.
Compressing & Optimizing Images
Large images can make your website look more attractive; however, they also increase your website’s loading time thus shows it down. So if your WordPress images are too large, think about optimizing them. Two useful plugins for this are:
Optimizing MySQL Database
An optimized database with no or less inactive or dead tables performs better than an unoptimized database. Hence to keep the performance of your website at its best, you should optimize your database by keeping it clean, free from unnecessary tables.
This can be down with following two plugins:
Enable Cache
Caching enhances the speed and performance of your website. It is a process of creating static versions of your website from its dynamic content and then serving them to visitors. This simply reduces the database queries and pages are rendered quickly in web browsers. Hence, leads to a faster web performance.
Two popular cache plugins are:
Where WP Super Cache is the best solution for shared hostings or cloud with a limited amount of resources. Whereas W3 Total Cache consumes more resources so it might slow down your website on some cheap hosting options.
Use CDN – Content Delivery Network
This is an option and it is up to you. Basically, CDN is a system of servers delivering images, web pages and other content to users based on their geographic location. Hence, they reduce latency and provides a faster loading of your website.
JetPack by WordPress.com plugin provides free CDN for images, the above-given cache plugin W3 Total Cache also provides you an option to enable CDN on your website. Other CDNs you can use on your WordPress site are MAX CDN, Sucuri and Cloud Flare. Though there are many more, use the one that suits your need and budget.