A firewall is a protective barrier between networks and security features. Firewalls are the streamlines of the codes positioned between the safe and unsafe networks, trustworthy and untrustworthy requests. For instance: While downloading a file online, a malicious content may also get downloaded with it (If you don’t have the firewall). Firewall differentiates the safe request (File you downloaded) and the unsafe requests (Malicious Content). This was about external differentiation. Firewalls are also deployed to differentiate the trustworthy access and untrustworthy access within the system because every department has its own confidential data that due to some reasons kept hidden from other departments of the same company. Access level is granted to the employs hierarchy wise. Not all the employs have access to all the files and folders.
This is the actual security guard deployed at the perimeter to protect your trusted private network. And by security guard I mean Physical Firewalls. All the data that is sent by the system or to the system has to pass through this physical firewall that filters the traffic and its allowance. Network Firewalls are installed at the perimeter of each external access point of the protected network. The protected network may have an external access point or internal.
It’s like whispering in the ear of the security guard and telling him whose access is allowed and whose not. Whispering here is the set of configured policies through which the data has to pass through. If the input or output access doesn’t meet these policies, then the guard (Application Firewall) blocks its access to the network. Unlike Network Firewalls, Application Firewalls don’t stand in the way of the data exchange, but monitor/supervise all the inputs/outputs and access.
It’s a fully equipped soldier at the front gate that uses its intelligence and physical strength to stop the trespassers. Both the above mentioned Firewalls are featured in it with UTM (Unified Threat Management) including network intrusion prevention, Antivirus, VPN, URL and content filtering, and Anti-spam. Multifunctional Firewalls are used in the case of local network (office PCs), LAN & WAN.
Ahaa! You have a personal bodyguard now! A personal Firewall is deployed on the single user computer. It controls the traffic hitting the computer’s Network Interface Controller (NIC). Not only on computers, but Personal Firewalls can also be deployed on smartphones and PDAs (Personal Digital Assistants).