This layer is like the sewage system or the electric line or the phone line that is coming into the house. They do not have any visual aspect but they connect with data. Like for instance in case of Twitter, the username, tweets, etc are all stored in a database, and the front-end layer gets that data from the backend layer. The above languages can be used to build the backend layer.
Hello Christopher, Users can save your website to their desktop by going into their internet browser (e.g. Chrome), navigating to settings and then manually creating a desktop icon that they can use. This process typically uses the website 'Favicon' as the default image for the desktop icon. Your favicon is the small image that appears in the tab next to your web page title at the top of a browser. For example, Wix's is a small version of the Wix logo, Gmail has a red and white envelope, while our site has a tiny WBE logo in a navy circle. You may need to do some research into how you can change your website's favicon, but if you do then this is how you can have a degree of control over how the desktop icon looks. I hgope that makes sense? - Tom
But testing gets complicated because some browsers only run on certain operating systems. Apple Safari runs on iOS and Mac OS, while Internet Explorer runs only on Windows. It's best to take advantage of services like Browsershots or Browserstack. Browsershots furnishes screenshots of your website as it will look in various browsers. Browserstack actually gives you full remote access to virtual machines so you can test your site in the most common environments. Alternatively, you can set up your own virtual machine, but that takes some expertise. (If you're going that route, Microsoft has some tools for developers including a ready-to-use virtual machine at modern.ie.) how to build a website