Linux hosting means that the servers on which websites are hosted have a Linux operating system. Linux is what is known as an open source operating system. Open source means that the coding is freely available publically, usually for free. A benefit to this is that many programmers all over the world have access to the code and can work together to improve it.
The Linux operating system uses many technologies that can add functionality to your website. For example, one of the technologies is PHP. PHP is used for making dynamic websites. Dynamic means that the website can change in appearance or function depending on user input. It makes the website more interactive which can increase the amount of time a user will stay on a site.
Another example is MySQL which is a database. A database stores information in such a way that it is easily accessed. For example, it might contain prices and quantities information on a website that sells a product. By using MySQL, website administration is made easier.