It is the software or hardware providing measures to prevent access to/from your network by controlling your incoming and outgoing network traffic. Nowadays, as per security needs, firewalls are supplied in two architecturally separate forms, namely Next Generation Firewall (NGFW) and Unified Threat Management (UTM).
Basic NGFW approaches considered functionality differences between these approaches such as application and user controls no longer pose a functionality difference by successful update of UTM solutions. Therefore, the concrete difference between these two approaches appears in scaling rather than functionality.
The different levels of UTM and NGDW solutions can be deployed at small, medium and large scale enterprises depending on network capacity, scale and needed functions. In addition to the Network Firewall, different functions such as Intrusion Prevention System (IPS), Web/Content Filtering, E-Mail Protection (AntiSpam), Gateway Antivirus, Data Loss Prevention (DLP), Web Application Firewall (WAF), Wireless Controller, Application Control, Sandboxing, Logging and Administrative Properties are determiner for the solution to be supplied.