Chapter 6: Networks

Vocabulary flashcards covering key terms and concepts from Chapter 6: Networks, including network types, devices, internet terms, web technologies, security threats, and authentication measures.

Network

A connection of two or more electronic devices.

Advantages of connecting a network

Sharing hardware/software resources; data sharing; ease of communication; network administrator controls users.

Disadvantages of connecting a network

Easier spread of malware; slower internet access; printer queues.

Local Area Network (LAN)

A network that uses cables and covers a small geographic area.

Wireless Local Area Network (WLAN)

A network that uses wireless radio waves to connect devices within a small geographic area; main technologies include Wi‑Fi and Bluetooth.

Advantages of WLAN over LAN

Lower cable costs; safer (fewer tripping hazards); easier to connect more devices.

Disadvantages of WLAN over LAN

Less secure; data transfer rate is slower than wired LAN; physical obstacles can affect signal.

Wide Area Network (WAN)

A network that covers a large geographic area, often using satellite technology (e.g., the Internet, bank ATM networks).

Network Interface Card (NIC)

A device component that allows a physical connection to a network; handles data to/from the computer and provides a MAC address.

MAC Address

A unique hardware address identifying a device on a network; six pairs of hexadecimal digits, colon-separated (example: FF:B3:A4:33:7E:F1). Assigned by the manufacturer and not easily changed.

MAC address format

Six groups of hexadecimal digits separated by colons; 6 pairs total.

Hub

Network device that connects multiple devices to form a LAN and broadcasts data packets to all connected devices.

Hub operation steps

1) Hub connects devices to form a LAN; 2) Hub receives a signal; 3) Hub broadcasts to all; 4) Intended recipient keeps data, others discard.

Switch

Network device that connects multiple computers to form a LAN and forwards data to the specific destination using MAC addresses.

Hub vs. Switch (differences)

Hubs broadcast to all devices; switches send packets to a specific device using a MAC-based lookup table; switches offer better security and efficiency.

Bridge

Device used to connect LANs so they act as one single LAN.

Router

Device that routes data packets to a specific destination; stores addresses and connects networks to the internet.

IP Address

A unique address identifying a device on a network; four decimal numbers (0-255) separated by dots; example: 192.108.158.1; assigned by an ISP.

Routing table

Table used by routers to determine where to send data packets; stores routes and IP addresses.

Routing steps (data between networks)

1) Data packet contains sender and destination IP; 2) Router reads destination IP; 3) Looks up route in routing table; 4) Checks path load and selects quickest path; 5) Forwards to next router; 6) Repeats until destination.

Firewall

A device/software placed between a user and an external network that filters traffic according to criteria to block unauthorized access and infections.

Internet Service Provider (ISP)

A company that provides internet access for a monthly fee; assigns an IP, monitors usage, and offers security services, email, cloud storage, and hosting.

Internet

Worldwide collection of interconnected networks; public and global; part of the infrastructure and service used by WWW.

Intranet

A private network accessible only within an organization; sits behind a firewall and supports internal communications and applications.

Extranet

Part of a company's intranet extended to external users (customers/suppliers) with controlled access.

World Wide Web (WWW)

The collection of web pages available on the Internet; a service accessed via web browsers.

Web page

A document written in HTML that can include text, images, videos, sounds, and hyperlinks.

Website

A collection of related web pages linked together by hyperlinks.

Hyperlink

A clickable link (text, image, or button) that navigates to another page or location.

HTML (HyperText Markup Language)

Markup language used to create web pages; uses tags to format content.

Content/Structure layer (web design)

Layer used to enter information and specify a webpage's layout/structure.

Presentation layer (web design)

Layer that defines formatting and style (CSS); maintains consistency of elements.

Behavior layer (web design)

Layer that controls interactive content and functionality (scripting).

WWW vs Internet Differences

WWW is a collection of web pages; the Internet is the underlying infrastructure and service; WWW is a service on the Internet.

Web server

A computer that stores web pages and has an IP address and domain name.

Web browser

Software that displays web pages by rendering HTML; provides address bar, navigation, tabs, bookmarks, history.

URL (Uniform Resource Locator)

A text-based address for a web page; includes protocol, domain, path, and filename.

URL components example

Protocol (http/https)://www.domain/type/path/filename (e.g., http://www.cie.org.uk/gcseict/giraffe.html).

Protocol

Rules agreed by the sender and recipient for data transfer between devices.

HTTP

The main protocol for transferring web page data; used to access the World Wide Web.

HTTPS

HTTP with encryption; uses SSL certificates to secure data transfer.

SSL (Secure Socket Layer)

Security protocol that uses encryption and digital certificates to securely exchange data over the internet.

FTP (File Transfer Protocol)

Protocol used to transfer files between computers; used for downloading from and uploading to file servers.

VOIP (Voice over Internet Protocol)

Protocol enabling internet-based telephony; supports audio and video calls; dependent on internet quality.

Accessing the Internet on desktop computers (advantages)

More stable/reliable connection; pages accessible on bigger screens; full keyboard/mouse.

Accessing the Internet on desktop computers (disadvantages)

Requires extra hardware; power dependency.

Accessing the Internet on laptops (advantages)

Portable; full keyboard/mouse; large screen for web pages.

Accessing the Internet on laptops (disadvantages)

Heavier and less portable than tablets/phones; screen size limitations.

Accessing the Internet on smartphones/tablets/phablets (advantages)

Very portable; convenient on the move.

Accessing the Internet on smartphones/tablets/phablets (disadvantages)

Smaller screens; not all sites accessible; signal stability may be lower.

Malware

Programs installed on a computer to delete, corrupt, or manipulate data illegally; delivered via email attachments, links, portable storage, or compromised software.

Virus

A program that reproduces itself within a computer and can delete/corrupt files, cause malfunctions, or fill storage.

Anti-virus software

Software that checks files against a database of known viruses; can quarantine or delete infected files; runs in background and can schedule scans.

Backing up and viruses

Backups do not reliably guard against viruses because infections can exist in backups and re-infect files.

Keylogging/Spyware

Software that records keystrokes and sends data to an attacker; can capture passwords and sensitive data.

Hacking

Gaining unauthorized access to a computer system; protections include firewalls, strong passwords, biometrics, two-factor authentication, and physical security.

Phishing

Fraudulent emails designed to obtain personal data; look for grammar errors, mismatched sender, generic greetings; protect with spam filters and by not clicking suspicious links.

Smishing

SMS-based phishing; fraudulent text messages seeking personal data; identify by similar signs as phishing and avoid unknown links.

Vishing

Voicemail phishing; attackers solicit personal data by posing as legitimate entities via voice calls.

Pharming

Malicious code redirects you to fake websites to steal data; verify URLs, use HTTPS, and trusted sources.

Shoulder surfing

Data theft by observing someone entering sensitive information (e.g., PIN) in public.

Card fraud

Illegal use of a credit/debit card; methods include shoulder surfing, cloning, keylogging, phishing, smishing, vishing, pharming.

Card cloning

Creating an unauthorized copy of a card's magnetic stripe data onto a new card; vulnerable to being used fraudulently.

Spam

Unsolicited junk email; can spread malware; recognize by poor grammar, missing logos, generic greetings; prevent with filters and disposable emails.

Authentication techniques

Methods to prove identity using forms of identification.

Something you own

A form of identification (e.g., card, USB dongle, mobile device) used for authentication.

Something you know

A form of authentication (e.g., password, PIN, email address).

Something you have

A form of authentication (e.g., biometrics, smart cards, tokens).

Where you are

Location-based authentication (e.g., GPS).

Two-factor authentication

Authentication requiring two separate methods to verify identity, increasing security.

User IDs and Passwords

User ID identifies the user; password is a secret string used with the ID to authenticate.

Password

A secret string of characters used to identify a user in an authentication system.

Strong password rules

Include at least one uppercase letter, one digit, one special character; at least 8 characters; not previously used; hard to crack.

Biometrics

Authentication using unique physical characteristics (e.g., fingerprint, iris, face, voice) or behavior.

Biometrics systems

Systems using body attributes as a password for authentication; advantages include security and convenience; disadvantages include cost and potential recognition errors.

Zero login

Authentication method combining biometric data and behavioral patterns without entering extra security information.

Magnetic stripe cards

Security cards with data on a magnetic stripe; advantages: easy to use and cheap; disadvantages: no encryption; wear out; readers sometimes fail.

Smart cards

Authentication cards with an embedded RFID chip; store data and PIN; faster and more secure than magnetic stripes but can be hacked or jammed.

Physical tokens

Hardware devices that generate a one-time password (OTP) for login, increasing security.

Electronic tokens

Software apps (e.g., on a smartphone) that generate a one-time password (OTP) for login.

Digital certificate

Electronic document used to verify a website and its owner; contains owner name, public key, issuer, issue/expiry dates, and signatures.

Encryption

Process of transforming readable data into ciphertext to prevent unauthorized access; requires keys to decrypt.

SSL (Secure Socket Layer)

Security protocol using encryption and digital certificates to secure data exchange over the internet; indicated by HTTPS and a lock icon.