Lesson 1

When physically securing a building from break-ins, the goal is to prevent any unauthorized person from ever gaining access to the building, so the company's assets will remain safe. The concept of network security is the same. The security administrator's goal is to restrict access to and from the compant's network.
A firewall is a secure computer system placed between a trusted network and one that is not trusted, such as the Internet. On one side of a firewall is a company's production network that is supervised, controlled, and protected by the network administrator. The other side contains a public network, such as the Internet.
This module discusses the mechanisms used to shield the internal network from unwanted activity.

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules and policies. Firewalls are typically implemented to protect a private intranet from unauthorized access while allowing access to the public Internet.
In a company's security policy, firewalls play a critical role in protecting the organization's network and systems from external threats such as hackers and malware. They can also be used to control access to specific network resources, such as blocking access to certain websites or limiting access to the network based on the location or device of the user. Additionally, firewalls can be configured to monitor and log all network traffic, which can be useful for detecting and responding to security incidents.