Data Communication and OSI Model - Vocabulary Flashcards

Vocabulary flashcards covering key terms and concepts from the Data Communication lecture notes, including data concepts, network types, OSI layers, protocols, and modern technologies.

Data

Raw facts and figures that can be processed to derive information; includes text, numbers, images, audio, and video.

Information

Data that has been processed and organized to provide meaning.

Data Communication

Exchange of data between two or more networked devices capable of sending and receiving data over a communication medium.

Sender

A device that transmits data over a network.

Receiver

A device that receives data over a network.

Message

The data or information exchanged between sender and receiver.

Medium (Transmission Medium)

The path (wired or wireless) through which the message travels between source and destination.

Protocol

A set of rules that governs data communications between parties.

Delivery

The data is delivered to the correct destination and user.

Accuracy

Data delivered without errors.

Timeliness

Delivery of data in a timely manner; real-time transmission for audio/video.

Jitter

Variation in packet arrival time, which can affect timeliness.

Text

Data consisting of letters; stored as bits and often encoded as ASCII or Unicode.

Numbers

Data consisting of digits 0–9.

Images

Visual data; a pixel is the smallest element; size depends on resolution.

Audio

Sound data; continuous data that can be recorded and broadcasted.

Video

Broadcasting of data in the form of pictures or moving images.

Simplex

One-way data transmission only.

Half duplex

Two-way transmission, but not at the same time.

Full duplex

Both parties can transmit and receive simultaneously.

Node

A device capable of transmitting or receiving data on a network.

Computer Network

A collection of nodes connected by links, enabling data communication with emphasis on reliability, security, and performance.

Local Area Network (LAN)

A network confined to a small geographic area, such as a building or floor.

Wide Area Network (WAN)

A network covering a large geographic area.

Metropolitan Area Network (MAN)

A network larger than a LAN but smaller than a WAN, typically spanning a city.

OS I Model

Open Systems Interconnection model; a seven-layer framework for standardizing communication.

Physical Layer

OSI Layer 1; handles the physical connection and transmission of raw bits (cables, NICs, switches).

Data Link Layer

OSI Layer 2; provides node-to-node data transfer and error detection/correction (Ethernet, Wi‑Fi, MAC addresses).

Network Layer

OSI Layer 3; handles delivery of packets across networks and routing (IP, routers).

Transport Layer

OSI Layer 4; ensures complete data transfer with error recovery and flow control (TCP/UDP).

Session Layer

OSI Layer 5; manages sessions between applications (establishing, maintaining, terminating connections).

Presentation Layer

OSI Layer 6; translates, encrypts, compresses data between application and network (SSL/TLS, JPEG).

Application Layer

OSI Layer 7; services end-user applications (HTTP, FTP, SMTP).

Internet Protocol (IP)

Protocol that routes packets across networks using IP addresses.

ARPANET

Precursor to the Internet; early network funded by ARPA.

World Wide Web (WWW)

System that provides user-friendly access to information globally, developed by Tim Berners‑Lee.

Tim Berners‑Lee

Inventor of the World Wide Web.

Cloud Computing

On-demand computing resources and services hosted remotely (e.g., AWS, Microsoft Azure).

Amazon Web Services (AWS)

Amazon’s cloud platform offering scalable computing resources and services.

Microsoft Azure

Microsoft’s cloud platform providing cloud services and tools.

3G

Third-generation mobile networks offering higher data speeds and multimedia services.

4G

Fourth-generation mobile networks with improved speed and IP-based communication.

5G

Fifth-generation mobile networks with very high speeds and low latency.

Internet of Things (IoT)

Network of internet-connected everyday objects that exchange data.

Encryption algorithms

Methods used to encode data to protect confidentiality and integrity.

Security protocols

Rules to protect data and communications (authentication, encryption, integrity).

ASCII

American Standard Code for Information Interchange; encoding for text.

Unicode

A comprehensive encoding standard supporting many writing systems.

Pixel

The smallest element of a digital image.

Resolution

The number of pixels in an image; determines size and clarity.

Alexander Graham Bell

Inventor of the telephone, groundwork for voice communication.

Samuel Morse

Pioneer of the telegraph; demonstrated long-distance coded messaging.

Guglielmo Marconi

Pioneer of radio; developed methods to transmit/receive radio waves.

Radio

Wireless transmission of signals.

Data Flow

Movement of data between devices; modes include simplex, half duplex, and full duplex.

Data Routing

Choosing the best path for data transmission between sender and receiver.

Encapsulation

Wrapping data with protocol information from one layer into another.

Segmentation and Reassembly

Dividing a message into smaller segments for transmission and reassembling them at the destination.

Connection Control

Managing connection-oriented data transfer for lengthy data items.

Multiplexing

Combining multiple signals or data streams into one transmission unit.

Ordered Delivery

Maintaining a specific sequence of data delivery using sequence numbers.

Transmission Services

Quality of Service-related services in data transmission.

Flow Control

Regulating the rate of data transfer to prevent receiver overload.

Error Control

Techniques for detecting and correcting errors in transmission.