Introduction to Computer Networks

Comprehensive vocabulary terms and definitions covering the fundamentals of computer networking, including topologies, data flow, and network categories.

Communications

The branch of technology concerned with the representation, transfer, interpretation, and processing of data among persons, places, and machines also known as information systems.

Telecommunication

Communication at a distance.

Data communications

The exchange of data between two devices via some form of transmission medium such as a wire cable.

Communication System Effectiveness

Depends on four fundamental characteristics: delivery, accuracy, timeliness, and jitter.

Message

The information or data to be communicated, which can include text, numbers, pictures, audio, and video.

Sender

The device that sends the data message, such as a computer, workstation, telephone handset, or video camera.

Receiver

The device that receives the message, such as a computer, workstation, telephone handset, or television.

Transmission medium

The physical path by which a message travels from sender to receiver, such as twisted-pair wire, coaxial cable, fiber-optic cable, or radio waves.

Protocol

A set of rules that govern data communications representing an agreement between the communicating devices.

Simplex

A data flow mode where the direction of data is one way all the time, such as from a monitor.

Half duplex

A data flow mode where the direction of data can change, but it only travels in one direction at any given time.

Duplex

A data flow mode where data can be sent in both directions simultaneously.

Network Performance

A network criterion often measured by transit time, response time, throughput, and delay.

Network Reliability

A criterion measured by the frequency of failure, the time it takes a link to recover from a failure, and the network's robustness in a catastrophe.

Network Security

Issues including protecting data from unauthorized access, protecting data from damage, and implementing policies for recovery from breaches.

Point-to-Point Connection

Provides a dedicated link between two devices where the entire capacity of the link is reserved for transmission between those two devices.

Multipoint Connection

Also called multidrop, it is a connection in which more than two specific devices share a single link either spatially or temporally.

Topology

The geometric representation of the relationship of all the links and linking devices (nodes) to one another.

Mesh Topology

A network layout where every device has a dedicated point-to-point link to every other node, providing high reliability and capacity.

Mesh Physical Link Formula

In a fully connected mesh network with $n$ nodes, the number of physical links needed is calculated as $n(n - 1) / 2$.

Star Topology

A configuration where each device has a dedicated point-to-point link only to a central controller called a hub.

Tree Topology

Also known as an extended star topology, it is often used with network devices like bridges, switches, and routers to reduce traffic.

Bus Topology

A multipoint configuration that uses drop lines and taps to connect nodes to one long cable acting as a backbone.

Ring Topology

A layout where each device has a dedicated point-to-point connection with only the two devices on either side of it, with signals rotating around the ring.

Local Area Network (LAN)

A network designed for a single organization, office, building, or campus that allows for resource sharing like printers and file servers.

Metropolitan Area Network (MAN)

A network that connects LANs together and provides access to Wide Area Networks, often owned by a private or public network operator.

Wide Area Network (WAN)

An international network using public, leased, or private equipment provided by international operators or carriers.

Client/Server Network

An arrangement where network services are located in a dedicated computer that responds to the requests of client computers.