Why aren't my changes showing up on my website?

If you are absolutely sure that you have saved the changes you made, then the most likely cause is that the files are cached on your computer.

(This means that your browser is being lazy, and is just giving you the same files over and over again, rather than going and fetching a brand new copy each time.)

To force your computer to go and get a new copy of the files, you need to do a “hard refresh”.

Usually you can do this by pressing ctrl+R or ctrl+f5 (on a PC) or cmd+r / cmd+f5 (on a Mac).

... But it can depend on what operating system and browser you're using. For the complete run-down on how to hard refresh (if the above didn't work for you), see refreshyourcache.com. 

If all else fails, try using a different browser or try using a friend’s computer. If they can see the changes you’ve made, then it’s probably cached on your computer.