[WordPress] 4 levels of caching

Good overview on: https://www.smarthomebeginner.com/wordpress-on-docker-traefik/#3_WordPress_Caching

Browser Caching: This is what tells the visitors browser to cache the files locally to speed up future site/page visits. We will set this up using Nginx. On Apache, this is accomplished using .htaccess files.

Server Caching: This caches static versions of pages (Page cache). We are going to accomplish this using Nginx FastCGI cache.

Frontend Caching: This means caching WordPress PHP files so they don’t have to be re-compiled for every visit. We are going to set this up using PHP OpCache.

Database Caching: This optimizes database queries by storing them in the RAM for faster delivery. We are going to use Redis for this.