If your website loads, but just looks miserable (plain white background, not your fonts, etc), or is not showing edits you recently made on the site – it is probably an issue with an outdated cache in your website or on your web host.
My experience with caches is primarily in WordPress sites, so this guide is highly targeted at that use-case.
WordPress Caching Plugins
This would be the first cache I would try to clear. Most caching plugins make it super easy to clear them, adding a button to the admin toolbar. I don’t recommend having more than one caching plugin activated at one time.
Caching Built-in to WordPress Themes
Some themes will have caching built in to them, and the option to clear or disable them is often in the theme settings, possibly in a “performance” related section.
Caching at your site host
Your web host may have caches that are automatically setup for your website. Steps to clearing these caches will vary greatly depending on the host.