If you are already using an AMP development system on your PC you can skip this. If not, if you are maintaining your website using a "site builder" application provided by your web host or editing your HTML on your PC then uploading it to test the changes, I recommend that you think about switching to using a development system that runs on your PC or Mac.
An AMP package is a pre-configured Apache web server and supporting programs. Using it you can maintain an exact copy of your site on your PC and test all changes before uploading them to your server. This can save you a lot of time and grief.
With a development system you would, for example, install a TalkBack upgrade on your PC and test it without fear of breaking your Internet connected system. When you were satisfied the upgrade worked properly, you would repeat the upgrade on your Internet connected system.
A development system also allows you to test style and layout changes without the possibility of visitors to your site seeing "broken" pages.
Xampp is one such system and is available for Windows, Mac and Linux. It is the package I use. It provides a relatively painless way to install and use a web server. The package includes a number of applications but the basic ones that are used for a simple development system are: Apache web server, MySQL, PHP, and phpMyAdmin.
Information on other packages can be found in this Wikipedia article.