Computer Networks Foundations and Architecture

Vocabulary practice flashcards covering foundational computer networking concepts, devices, types, performance metrics, design issues, and reference models.

Computer

An electronic device that processes data according to instructions provided by software programs, taking input (data), processing it using a central processing unit (CPU), storing information, and producing output (results).

Communication (in a Computer Network)

The process of sending and receiving data or digital information between two or more connected devices using specific rules and physical or wireless paths, relying on a sender, receiver, message, transmission medium, and shared protocols.

Data (in a Computer Network)

Raw information made of binary code (ones and zeros) that is broken down into small pieces called packets to move safely from one device to another.

Network

A general term for a group of connected people, objects, or systems (such as social, transportation, or telephone networks).

Computer Network

A group of interconnected computers and devices (like phones and printers) that communicate and share resources using wired or wireless media.

Hub

A basic Layer 1 (Physical Layer) networking device that receives incoming signals through one port and repeats/broadcasts them to all other ports without checking destination addresses, creating a single collision domain.

Passive Hub

A type of hub that simply passes the signal along without altering or regenerating it.

Active Hub

A type of hub that regenerates and amplifies incoming signals before forwarding them.

Intelligent Hub

A type of hub that provides basic network monitoring and management capabilities.

Bridge

A Layer 2 (Data Link Layer) networking device that connects two or more LAN segments and uses MAC addresses to filter and forward frames, dividing the network into separate collision domains.

Transparent Bridge

A bridge that automatically learns MAC addresses and forwards or filters frames across LAN segments.

Source Routing Bridge

A bridge mainly used in Token Ring networks where the routing path is specified by the source device.

Translational Bridge

A bridge used to connect different types of LAN technologies, such as Ethernet and Token Ring.

Switch

A Layer 2 (Data Link Layer) device that learns MAC addresses, stores them in a MAC address table, and forwards frames exclusively to the port connected to the destination device.

Router

A Layer 3 (Network Layer) networking device that connects different networks and forwards data packets using IP addresses and routing tables.

Gateway

A networking device or node that connects two different networks using different protocols or architectures, acting as an entry/exit point and converting protocols when necessary.

Modem

A communication device (Modulator-Demodulator) that converts digital computer signals to analog signals for transmission over media and converts received analog signals back into digital data.

Repeater

A networking device that receives weak signals, regenerates and reshapes them, and retransmits them to extend transmission distance and overcome signal attenuation.

Access Point (AP)

A networking device connected to a wired network (usually via Ethernet) that broadcasts a Wi-Fi signal (SSID) to allow wireless devices to connect to a LAN.

Network Interface Card (NIC)

A hardware component that enables a device to connect to a network (via Ethernet or Wi-Fi), handling data transmission using a unique 48-bit MAC address.

Personal Area Network (PAN)

A short-range network connecting personal devices around a single user within a coverage range of $1\text{--}10\text{ meters}$ using technologies like Bluetooth, NFC, or Infrared.

Local Area Network (LAN)

A network that connects computers and devices within a small geographical area such as a room, building, office, or campus using Ethernet or Wi-Fi.

Metropolitan Area Network (MAN)

A network spanning a larger geographical region than a LAN, typically covering an entire city or town using Fiber Optics, Microwave, or Metro Ethernet.

Wide Area Network (WAN)

A network connecting devices across large geographical distances such as countries or continents using leased lines, satellite links, or the Internet.

Internetwork

A system formed by interconnecting two or more independent computer networks using Layer 3 networking devices like routers or gateways to enable cross-network communication.

Intranet

A private network used within an organization that is accessible exclusively to authorized internal users.

Extranet

A private network that grants controlled, limited access to authorized external users such as partners, suppliers, or customers.

Internet

A worldwide global internetwork that connects millions of public, private, academic, and government networks.

Connection-Oriented Service

A service (like TCP) that establishes a dedicated communication path via a handshake before transmitting data, ensuring ordered, reliable, and error-checked delivery.

Connectionless Service

A service (like UDP) that transmits data packets (datagrams) independently without prior connection setup, offering lower latency but no guarantee of delivery order or arrival.

ISO (International Organization for Standardization)

An international organization that develops global standards, including the 7-layer OSI reference model for networking.

IEEE (Institute of Electrical and Electronics Engineers)

An organization that sets technical standards for communication and computing, such as the IEEE 802 standard family for LANs (802.3 Ethernet, 802.11 Wi-Fi).

IETF (Internet Engineering Task Force)

An organization that develops and maintains open Internet protocols (e.g., TCP, IP, HTTP, DNS) published as RFC documents.

ITU-T (International Telecommunication Union – Telecommunication Standardization Sector)

An international body that formulates standards and recommendations for telecommunication networks, voice, data, and multimedia systems.

Bandwidth

The maximum theoretical amount of data that can pass through a network connection in a given time period, measured in bps, Mbps, or Gbps.

Throughput

The actual measured rate of data successfully transmitted over a network in a given period of time.

Latency (Delay)

The total time required for a packet of data to travel from its source to its destination, measured in milliseconds ($\text{ms}$).

Jitter

The measure of variation in packet transit delay across a network, which can disrupt real-time voice and video quality.

Packet Loss

The condition where one or more data packets fail to reach their intended destination during network transmission.

OSI Reference Model

A 7-layer conceptual framework (Physical, Data Link, Network, Transport, Session, Presentation, Application) developed by ISO to standardize network functions.

TCP/IP Model

A 5-layer practical networking framework (Physical, Data Link, Network/Internet, Transport, Application) created for real-world Internet communication.

MAC Address

A 48-bit hardware address assigned to a network interface card used for device identification within a Local Area Network.

Flow Control

A mechanism implemented across network layers to ensure a fast sending host does not overwhelm a slower receiving host with data.

Statistical Multiplexing

A network design technique where data channels dynamically allocate fractions of bandwidth or time slots to active hosts rather than assigning dedicated paths.