What do you understand by the firewall?
A firewall is a form of security for your server. It is uniquely designed to protect and prevent your server from unauthorized access or rather to protect from a private network. You can use a hardware or software firewall, or even a combination of both. It ensures a high level of network security that implements the filtering of ongoing and outgoing traffic. This is based on a set of user-based rules.
In simple words, a firewall eliminates and isolates any unwanted network communication and ensure the free flow of legitimate communication. It stands necessary to keep a firewall for your server.