Network uses a single bus, if two or more electrical signals were sent at the same time, they would overlap and collide, making both signals unintelligible. So, unsurprisingly, Ethernet also defined a specification for how to ensure that only one device sends traffic on the Ethernet at one time. Otherwise, the Ethernet would have beenunusable. This algorithm, known as the carrier sense multiple access with collision detection (CSMA/CD) algorithm, defines how the bus is accessed.
In human terms, CSMA/CD is similar to what happens in a meeting room with many attendees. It’s hard to understand what two people are saying at the same time, so generally, one person talks and the rest listen. Imagine that Bob and Larry both want to reply to the current speaker’s comments. As soon as the speaker takes a breath, Bob and Larry both try to speak. If Larry hears Bob’s voice before Larry makes a noise, Larry might stop and let Bob speak. Or, maybe they both start at almost the same time, so they talk over each other and no one can hear what is said. Then there’s the proverbial “Pardon me; go ahead with what you were saying,” and eventually Larry or Bob talks. Or perhaps another person jumps in and talks while Larry and Bob are both backing off. These “rules” are based on your culture; CSMA/CD is based on Ethernet protocol specifications and achieves the same type of goal.
In human terms, CSMA/CD is similar to what happens in a meeting room with many attendees. It’s hard to understand what two people are saying at the same time, so generally, one person talks and the rest listen. Imagine that Bob and Larry both want to reply to the current speaker’s comments. As soon as the speaker takes a breath, Bob and Larry both try to speak. If Larry hears Bob’s voice before Larry makes a noise, Larry might stop and let Bob speak. Or, maybe they both start at almost the same time, so they talk over each other and no one can hear what is said. Then there’s the proverbial “Pardon me; go ahead with what you were saying,” and eventually Larry or Bob talks. Or perhaps another person jumps in and talks while Larry and Bob are both backing off. These “rules” are based on your culture; CSMA/CD is based on Ethernet protocol specifications and achieves the same type of goal.