• Skip to main content
  • Skip to primary sidebar
  • Skip to secondary sidebar
  • Skip to footer

Computer Notes

Library
    • Computer Fundamental
    • Computer Memory
    • DBMS Tutorial
    • Operating System
    • Computer Networking
    • C Programming
    • C++ Programming
    • Java Programming
    • C# Programming
    • SQL Tutorial
    • Management Tutorial
    • Computer Graphics
    • Compiler Design
    • Style Sheet
    • JavaScript Tutorial
    • Html Tutorial
    • Wordpress Tutorial
    • Python Tutorial
    • PHP Tutorial
    • JSP Tutorial
    • AngularJS Tutorial
    • Data Structures
    • E Commerce Tutorial
    • Visual Basic
    • Structs2 Tutorial
    • Digital Electronics
    • Internet Terms
    • Servlet Tutorial
    • Software Engineering
    • Interviews Questions
    • Basic Terms
    • Troubleshooting
Menu

Header Right

Home » ECommerce » Basic » Firewall – What do you mean by Firewall?
Next →
← Prev

Firewall – What do you mean by Firewall?

By Dinesh Thakur

This is a software/hardware combination that connects an organization’s internal networks to the Internet. As such, its primary concern is security: it uses rules to determine what information can be passed in either direction, based on the originator address, the server address and the type of information to be transferred. In plain English something that monitors all communication between the company network and the Internet and makes sure that this communication is legitimate. Broadly speaking there are two main types of firewall: network level and application level.

We’ll be covering the following topics in this tutorial:

  • Network Level Firewalls
  • Application Level Firewalls

Network Level Firewalls

These accept or reject messages based on the source address of that message. To explain, every message is split up into smaller packets of data before being sent out over the Internet. Naturally this packet of data carries its destination address so any computer it passes through knows where to send it next, however it also carries the source address which is what the network level firewall looks for. If the data packet originates from a known, or pre-defined, address it is let through into the company system; if not it is rejected.

Network level firewalls are what is known as transparent to the user which means no-one knows they are there. They operate without the users being aware of their existence. While this can make them popular they are by no means the best solution for high security organizations as they can be defeated. It is possible to forge the source address on data packets and so fool the firewall into thinking they come from an approved source.

Application Level Firewalls

These perform a much more sophisticated analysis of the data passing through them according to criteria set by each individual company. Although more secure this auditing process takes time which means the system will run that much slower.

Additionally it could require extra training on the part of the user.

As a further refinement both types of firewall could be used in combination. Low grade information could be protected by a network level firewall to take advantage of its speed while high grade information could be protected behind an application level firewall to take advantage of its greater security. In this way a great deal of safety can be built into the system – and yet security will still not be absolute. Firewalls cannot prevent a virus being downloaded nor are they proof against sabotage or stupidity from personnel within the company.

Something else a firewall cannot do is set the security policy for the company. They are without doubt the physical representation of that security policy, and they work according to the guidelines laid down in that same security policy, but they cannot create it themselves. Only humans can do that.

You’ll also like:

  1. FIREWALL: Explain Types of Firewall Architectures
  2. What is Firewall?
Next →
← Prev
Like/Subscribe us for latest updates     

About Dinesh Thakur
Dinesh ThakurDinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular Computer Notes blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps.

Dinesh Thakur is a Freelance Writer who helps different clients from all over the globe. Dinesh has written over 500+ blogs, 30+ eBooks, and 10000+ Posts for all types of clients.


For any type of query or something that you think is missing, please feel free to Contact us.


Primary Sidebar

E Commerce

E Commerce Tutorials

  • EC - Home
  • EC - History
  • EC - Types
  • EC - Characteristic
  • EC - Limitations
  • EC - EDI Architecture
  • EC - Electronic Payment system
  • EC - EDI Standards
  • EC - Advantage
  • EC - EPT Issues
  • EC - Extranet
  • EC - Firewall
  • EC - E-Business Models
  • EC - Security Issues
  • EC - VPN
  • EC - CRM
  • EC - Electronic Cash
  • EC - B2B
  • EC - Electronic Wallet
  • EC - EDI

Other Links

  • E Commerce - PDF Version

Footer

Basic Course

  • Computer Fundamental
  • Computer Networking
  • Operating System
  • Database System
  • Computer Graphics
  • Management System
  • Software Engineering
  • Digital Electronics
  • Electronic Commerce
  • Compiler Design
  • Troubleshooting

Programming

  • Java Programming
  • Structured Query (SQL)
  • C Programming
  • C++ Programming
  • Visual Basic
  • Data Structures
  • Struts 2
  • Java Servlet
  • C# Programming
  • Basic Terms
  • Interviews

World Wide Web

  • Internet
  • Java Script
  • HTML Language
  • Cascading Style Sheet
  • Java Server Pages
  • Wordpress
  • PHP
  • Python Tutorial
  • AngularJS
  • Troubleshooting

 About Us |  Contact Us |  FAQ

Dinesh Thakur is a Technology Columinist and founder of Computer Notes.

Copyright © 2025. All Rights Reserved.

APPLY FOR ONLINE JOB IN BIGGEST CRYPTO COMPANIES
APPLY NOW