Unit 1: Computer Networks – Architecture, Services, Systems, and Topologies

Vocabulary flashcards covering key concepts from the lecture notes on network architectures, systems, services, and topologies.

Network Architecture

The physical and logical design of software, hardware, protocols, and media for data transmission; how computers are organized and how tasks are allocated.

Peer-To-Peer (P2P) Network

A network where all computers have equal privileges and responsibilities; no dedicated server; suitable for small environments (often up to about 10 computers).

Client/Server Network

A network model where clients access resources from a central server; the server handles security, management, and resource provisioning.

Centralized System

A computing architecture where processing and storage are located on a central server (or tightly connected servers); single point of control.

Decentralized System

A computing architecture with multiple nodes sharing control without a single central authority; increases fault tolerance and resilience.

Distributed System

Multiple independent nodes work together over a network to appear as a single system; aims to improve performance, reliability, and scalability.

Directory Services

Software that maps names to values (such as user credentials) and stores access information; supports authentication and authorization.

Authentication

Process of verifying a user’s identity (e.g., credentials) at login or periodically.

Authorization

Process of granting access rights after successful authentication.

DNS (Domain Name System)

Maps IP addresses to domain names to make addresses easier to remember; resolves website names to IPs in the backend.

File Services

Sharing and transferring files over a network.

File Sharing

Enabling users to share files, either on a central server or on their own computer.

File Transfer

Copying or moving files between computers over a network.

Email Services

Electronic mail system with one or more email servers; users have unique IDs; messages routed via servers.

Social Networking

Online platforms that connect people and allow sharing of thoughts, pictures, and videos.

Internet

Global network of interconnected networks enabling communication and access to information.

Internet Chat (IRC)

Instant text-based communication between hosts; now often includes voice and video chat.

Remote Access / Remote Desktop

Accessing data on a remote computer from another device.

Web Services

Network-based services (web applications, APIs, etc.) that provide functionality over a network.

Resource Sharing

Sharing resources such as servers, printers, and storage to use them efficiently.

Databases

Structured storage of data; supports processing and querying to enable decision-making.

Cloud Computing

Provision of on-demand computing resources (servers, storage, apps) hosted by providers like AWS, Azure, or GCP.

CDN (Content Delivery Network)

Distributed servers that deliver content based on users’ geographic location to reduce latency.

Blockchain

Decentralized ledger technology that records transactions across multiple nodes for security and transparency.

DeFi (Decentralized Finance)

Financial services built on blockchain technology, enabling lending, borrowing, and trading without intermediaries.

P2P File Sharing

Peer-to-peer networks where users directly share files without a central server (e.g., BitTorrent).

De Facto Standard

A standard widely adopted in practice but not officially approved by standardization bodies.

De Jure Standard

An officially approved standard established by recognized bodies like ANSI, ISO, or IEEE.

Interoperability

The ability of different devices and systems to work together using common protocols and standards.

Security Baseline

Established security principles and best practices (e.g., encryption, authentication, access controls) used to protect networks.

Vulnerability Management

Process of identifying, assessing, and mitigating security vulnerabilities, including scanning and testing.

NOS (Network Operating System)

An operating system that provides resources and services to network clients (e.g., Windows Server, UNIX).

Single Point of Control

A centralized point in a system where administration and control are concentrated.

Single Point of Failure (SPOF)

A component whose failure could bring down the entire system or network.

Geographical Distribution

Nodes distributed across different physical locations, typical of distributed systems.

Concurrency

Multiple nodes performing tasks simultaneously to improve performance.

Fault Tolerance

System ability to continue operating despite failures, through redundancy and replication.

Scalability

Ability to grow by adding resources or nodes without performance loss.

Transparency

The complexity of the distributed system is hidden from users; it appears as a single system.

Token

A frame circulated in token-passing topologies that grants permission to transmit.

Token Passing

Access method in which a token is passed among nodes to authorize sending data.

Bus Topology

All nodes connected to a single backbone cable; CSMA is commonly used; inexpensive but with longer cabling and collision issues.

Ring Topology

Nodes connected in a ring; data flows unidirectionally; uses token passing to control access.

Star Topology

Each node connects to a central hub or switch; easy troubleshooting; potential single point of failure.

Tree Topology

Hybrid structure combining bus and star topologies; hierarchical root and descendant nodes.

Mesh Topology

Nodes interconnected with multiple redundant paths; highly reliable and scalable, often used in WAN and wireless networks.

Hybrid Topology

Combination of two or more different topologies; flexible but design can be complex and costly.