What is difference between IDS,firewall and anti virus

Thanks

google, altavista, etc .

Or is that too rude? (a)

IDS = Intrusion Detection system


There are many forms of IDS (Network IDS) (Host IDS)

Network IDS will Generally Capture all Traffic on the network
Host will Capture Traffic for Individual Host

IDS detects attempted attacks using Signatrue and Patterns much like an Anti Virus App will.

There is also IPS - Intrusion Prevention System, this can detect an attempted attack and shun or dynamically change an ACL.



Anti Virus - will Capture attempted Infections of Files or email, the general infection will be a trojan and or Virus/Malware, i generally use a AV scanner + Spyware/Malware scanner

Firewall

Generally but not limited to a Perimeter of a Network, Firewalls can be Sophisticated or not depending on Config and features.

Firewall will scan TCP/IP packets based on Source and Destination then check again a list ( ACL ) and block/Allow traffic accordingly, some firewalls can provide Layer 7 Traffic Scaning ( Deep Packet Inspection) for instance rules can be setup for Applications,
Some Firewalls like ASA can have IDS/AV intergrated depending on model.

This is a very Deep Subject and this is my brief desription of them.

If you need more info then Chojin is right use Google to find out more about each subject.

Thanks

google, altavista, etc .

Or is that too rude? (a)

Ask a broad question...provide a broad answer. Ask a specific question...provide a specific answer, but telling people straight forward to go to Google or whatever is not only rude but also defeats the purpose of a forum (IMHO). Forums are preferred over search engines because they provide an avenue to directly ask questions and directly receive answers. Search engine questions and answers aren't always direct and clear. Furthermore, on a forum, you're asking people for answers. On search engines, you're essentially asking a web interface to ask a database for answers...obviously, the former is preferred.

Yes, doing prior research is always preferred, but in this case, I'd have to guess that shivanandkadwadkar is new to forum culture, so rather than slamming him/her with "F*** off! Search Google!" I'd answer with a broad answer that would help him/her break his/her question down to a specific question.