3 types of firewalls
1. PACKET-FILTERING FIREWALL
- Make use of router (with care filters message to/from the network & internet)
that connects internal network
2. CIRCUIT-LEVEL FIREWALL
- A computer is installed between the internet & internal network
- allows a higher level of authentication logic into the filtering process.
3. Application-Level Firewall
- uses of isolation mechanism that is tailored to each application.
- most complete form of security.

BUSINESS APPLICATIONS OF THE INTERNET
1.MARKETING RESEARCH
2.COMPETITIVE ADVANTAGE
3.RETAILING INFORMATION