I will try to explain how the OSI model works so that it is easier to understand for those that have trouble with the concept. Think of communications in terms of people. Each person that you talk to is like a computer with its own capacity to compute and / or calculate information. If I speak directly with you and share information, that is like a peer to peer network. There really isn't any "hardware" at …showed first 75 words of 658 total…

…showed last 75 words of 658 total…layer, I may not want people in my room to talk about sex or drugs. These are "services" that I won't allow. So, as a technician I can manage the security of the network so that I can control what type of communications occur. I may also NOT want a particular crowd of people to enter my room. So, I can install a firewall to filter out who is allowed to enter my room (network).