A website is a set of applications composed in different programming languages and frameworks, thematically linked with each other so that they belong together. Let’s take the MegiTeam website as an example. https://www.megiteam.pl is a homepage, https://www.megiteam.pl/blog leads to the blog, https://facebook.megiteam.pl leads to the FB fanpage. All of these websites are working at the mutual domains – the same addresses for megiteam.pl, megiteam.com, megivps.pl etc. The PHP-based websites are the exeptions to this rule – you can add the independent content under separate domains.
Each website is a server account with the same name as the name of a website. You can log on to it through ssh, sftp or ftp. You will get the access data after you set up a website.
You can add/remove your websites whenever you want, as long as you have the money on your account. You can run your websites on a shared hosting or a cloud VPS.