Firewall

Website security is important, and a firewall is an essential part of protecting your website from attacks. Think of your firewall as security guards who have been given a set of rules to evaluate whether or not to let guests in. This makes sure that genuine visitors have access to your website, but keeps unwanted visitors out.
With shared hosting (and generally cloud and managed hosting), your hosting provider will usually have firewalls already installed on the server, and you don’t have any control over these. VPS and dedicated servers give you the option to install your own additional firewalls, increasing the level of security.