Abstract: The Internet is expanding with a tremendous speed so as its Security. Security is an important field that consists of the provisions made in underlying computer network infrastructure, policies adopted by the network administrator to protect the network, the network-accessible resources from unauthorized access and the effectiveness of these measures combined together. Personal, government, and business applications continue to multiply on the Internet and these work-based application and services can pose security risks to individuals and to information resources of companies and governments. Information is an asset that must be protected. Network security is more challenging than ever, as today’s corporate networks become increasingly complex.
Keywords: Internet, Network Security, Firewall, Attacks, Threats, Phishing, DoS, Cookies.