---
title: "Firewall Explained to Kids and Adults"
description: "Learn about firewalls: network security, types, and how they protect us."
image: "https://assets.bytebytego.com/diagrams/0191-firewall.jpeg"
createdAt: "2024-02-16"
draft: false
categories:
  - security
tags:
  - "Network Security"
  - "Firewall"
---

![](https://assets.bytebytego.com/diagrams/0191-firewall.jpeg)

A firewall is a network security system that controls and filters network traffic, acting as a watchman between a private network and the public Internet.

They come in two broad categories:

*   Software-based: installed on individual devices for protection

*   Hardware-based: stand-alone devices that safeguard an entire network.

Firewalls have several types, each designed for specific security needs:

### Packet Filtering Firewalls

Examines packets of data, accepting or rejecting based on source, destination, or protocols.

### Circuit-level Gateways

Monitors TCP handshake between packets to determine session legitimacy.

### Application-level Gateways (Proxy Firewalls)

Filters incoming traffic between your network and traffic source, offering a protective shield against untrusted networks.

### Stateful Inspection Firewalls

Tracks active connections to determine which packets to allow, analyzing in the context of their place in a data stream.

### Next-Generation Firewalls (NGFWs)

Advanced firewalls that integrate traditional methods with functionalities like intrusion prevention systems, deep packet analysis, and application awareness.