The web servers in your hosting plan put together your web pages, packages them up and ships them out to viewers who ask for them. The follow a very specific set of instructions from the web server software and the software that runs your website. But, what if you have a special situation where you want the server to do something different from the regular instructions? Here are some examples:
1. You reorganized your site, and some … or many … of your pages have new addresses. People out there are going to click links, from Google and other sites, that go to the old address. Normally, your web server would just send them an “OOOOPS! That page doesn’t exist” message. You need a way to tell the server, if people ask for this address, send them to this other address.
2. You have a secure certificate for your website, so your addresses start with https://, instead of http://. But you know that some people will get it wrong and go to http://. So, you want the server to show https:// either way.
These are the types of cases where the .htaccess file comes in handy.