IT

What is the Internet?

The Internet is the physical infrastructure of interconnected networks and devices.

What is the World Wide Web?

The WWW is a collection of linked documents and resources accessible via the Internet.

How do DNS servers work?

They translate domain names into IP addresses for routing requests over the Internet.

What is the difference between IPv4 and IPv6?

IPv6 provides more IP addresses and includes built-in encryption, unlike IPv4

What is a web browser?

A software tool that retrieves and displays web pages (e.g., Chrome, Firefox).

What is the purpose of HTTP?

HTTP is a protocol used for transferring web pages from servers to browsers.

What are some uses of cloud computing?

Cloud computing provides remote storage, processing, and software services.

Name three cloud service models.

IaaS (Infrastructure as a Service), PaaS (Platform as a Service), SaaS (Software as a Service).

What is HTML?

HTML (HyperText Markup Language) is used to structure and display content on web pages.

What is the function of CSS?

CSS (Cascading Style Sheets) controls the visual style and layout of a web page.

What is an API?

An API (Application Programming Interface) defines how software components communicate.

What are cookies used for?

Cookies store information on a user's device to enhance website functionality and track usage.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data format for exchanging data online.

What is XML?

XML (Extensible Markup Language) describes and organizes data in a structured format.

What are JSPs (Java Server Pages)?

JSPs are server-side technologies used to dynamically create web pages.

What is the Semantic Web?

A web enhancement aiming to improve data indexing and enable AI-driven searches.

What is the role of ICANN? (Internet Corporation for Assigned Names and Numbers)

ICANN manages domain names and IP addresses on the Internet.

What is a URL?

A URL (Uniform Resource Locator) specifies the location of a web resource.

What is web analytics?

Web analytics involves collecting and analyzing website usage data (e.g., visitor behavior).

What is the role of a web server?

A web server stores and delivers web pages upon request from browsers.

What are scripting languages?

Scripting languages are interpreted, not compiled, and are often used for automating tasks. Examples include Python, Bash, and JavaScript.

How are variables handled in Bash?

Variables are not declared explicitly. They are assigned values using VAR=value, and their values can be retrieved with $VAR.

What is the purpose of the echo statement in Bash?

It outputs text or variable values to the terminal or a file.

How is input provided in Bash?

Input is handled using the read command, which assigns user input to variables.

How do you access script parameters in Bash?

Script parameters are accessed using $1, $2, etc., and $@ refers to all parameters.

What is $0 in a Bash script?

$0 stores the name of the script.

What are file condition tests in Bash?

Examples include -e (exists), -f (is a file), -d (is a directory), and -r (is readable).

What are the comparison operators for integers in Bash?

-eq (equals), -ne (not equals), -gt (greater than), -lt (less than).

How are strings compared in Bash?

Strings are compared using == (equals) and != (not equals).

What is the structure of a Bash if statement?

if [ condition ]; then

commands

fi

How do you include else in a Bash if statement?

if [ condition ]; then

commands

else

other_commands

fi

What is a for loop in Bash?

for var in list; do

commands

done

What is a while loop in Bash?

while [ condition ]; do

commands

done

How do you perform arithmetic in Bash?

Arithmetic is done using $((expression)), e.g., SUM=$((NUM1 + NUM2)).

What is the % operator in Bash?

It calculates the remainder (modulus) in integer arithmetic

How are complex conditions written in Bash?

Use [[ ... ]] with logical operators like && (and) or || (or).

How do you check if a file is writable in Bash?

Use the -w condition, e.g., [ -w filename ].

What is $# in Bash?

It represents the number of parameters passed to the script.

Why use #!/bin/bash at the start of a script?

It specifies the interpreter to use for running the script.

What is the purpose of $@ in a Bash script?

$@ represents all command-line arguments as a list.

What is a computer network?

A collection of interconnected computers and resources that can communicate with each other, sharing data, printers, and files.

Name three advantages of computer networks.

• Resource sharing.

• Data sharing.

• Easy communication.

What is a protocol in networking?

A set of rules for formatting and processing data on a network.

What is a bandwidth?

The amount of data that can be transmitted over a network in a given time, often measured in bits per second.

Define modulation and demodulation.

• Modulation: Converts digital signals to analog for transmission.

• Demodulation: Converts analog signals back to digital.

What is a hub in networking?

A device that broadcasts incoming messages to all connected devices.

What is a switch in networking?

A device that directs messages to a specific destination using network addresses.

What is a router?

A device that connects multiple networks and routes data based on destination addresses.

What is the difference between a circuit-switched and packet-switched network?

• Circuit-switched: Maintains a dedicated path for communication.

• Packet-switched: Breaks messages into packets that take independent paths.

What is a star topology?

A network layout where all devices connect to a central hub or switch.

What is a bus topology?

A network layout where devices are connected to a single communication line.

Name the seven layers of the OSI model.

Application, Presentation, Session, Transport, Network, Data Link, and Physical layers.

What is the function of the transport layer in the OSI model?

Divides messages into segments, provides error correction, and manages flow control.

How does TCP differ from UDP?

• TCP: Reliable, uses handshaking and sequence numbering.

• UDP: Faster, focuses on speed over reliability.

What is IPv4?

A 32-bit addressing scheme providing over 4 billion unique addresses.

What is IPv6?

A 128-bit addressing scheme designed to replace IPv4, supporting vastly more addresses.

What is a virtual private network (VPN)?

A secure connection that allows users to access a private network remotely.

What does NAT (Network Address Translation) do?

Translates internal IP addresses to external ones, providing anonymity and conserving IP addresses.

What is the difference between a client-server and peer-to-peer network?

• Client-server: Centralized servers provide services to clients.

• Peer-to-peer: Resources are shared equally among devices.

What is a firewall?

A security tool that monitors and controls incoming and outgoing network traffic based on predefined rules.

What is a computer network?

A collection of computing devices connected to communicate and share resources, either through wired or wireless connections.

What is a protocol in networking?

A set of rules defining how data is formatted and processed on a network.

What is the purpose of a file server?

A computer dedicated to storing and managing files for network users.

Define a node in a computer network.

A node, or host, is any device connected to a network.

What is the client/server model?

A model where clients send requests and servers respond, commonly used for file and web servers.

What is a local-area network (LAN)?

A network connecting a small number of devices within a close geographical area.

What is a wide-area network (WAN)?

A network that connects multiple LANs across large geographical distances.

What is Ethernet?

The industry standard for LAN technology, originally using a bus topology but now supporting star topology.

What is the role of a router in a network?

A router connects multiple networks and directs packets to their destination.

What is the function of a DNS?

The Domain Name System translates human-readable hostnames into numerical IP addresses.

What is packet switching?

A method of dividing messages into packets, routing them independently, and reassembling them at the destination.

What is TCP?

Transmission Control Protocol ensures reliable data transfer by sequencing and acknowledging packets.

What is UDP?

User Datagram Protocol prioritizes speed over reliability, commonly used for streaming and DNS.

What is the role of the transport layer in TCP/IP?

It manages data flow, reliability, and segmentation of messages into packets.

Name three models of cloud computing.

• IaaS: Infrastructure as a Service.

• PaaS: Platform as a Service.

• SaaS: Software as a Service.

What is the difference between public and private clouds?

• Public clouds: Accessible by any subscriber.

• Private clouds: Restricted to specific groups or organizations.

What is latency in networking?

The time it takes for a data packet to travel from source to destination, a measure of speed.

What is a database?

An organized collection of data stored centrally or across multiple locations, structured based on schemas and relationships.

What is a Database Management System (DBMS)?

Software for creating, storing, maintaining, and accessing database files, making database use more efficient.

Name the types of traditional DBMS.

• Hierarchical DBMS.

• Network DBMS.

• Relational DBMS (RDBMS).

• Object-Oriented Relational DBMS.

What is a distributed database?

A database stored across multiple computers, either in the same location or scattered over networks.

What is a NoSQL database?

A non-relational database optimized for unstructured or semi-structured data, suitable for web and large-scale applications.

Compare OLTP and OLAP databases.

• OLTP: Focuses on transaction processing (insert, update, delete).

• OLAP: Focuses on analytical processing for insights, forecasting, and planning.

What does ACID stand for in databases?

Accuracy, Consistency, Isolation, and Durability – key properties for data integrity.

What is a schema in a database?

A defined structure specifying tables and data types, acting as a contract for how data is organized.

What is a relational database table?

A collection of records where relationships among data are defined as rows (records) and columns (fields).

What is SQL?

Structured Query Language, used for data manipulation and querying relational databases.

Provide an example of a SQL query to retrieve all customers named "John".

SELECT * FROM Customer WHERE firstName = 'John';

What are the advantages of NoSQL databases?

• No fixed schema.

• Fault tolerance with data replication.

• Horizontal scalability.

• High write performance.

What are the disadvantages of NoSQL databases?

• No joins or referential integrity across partitions.

• Lack of declarative query languages like SQL.

• Relaxed ACID properties.

Name four types of NoSQL databases.

1. Document-based (e.g., MongoDB).

2. Key-value (e.g., DynamoDB).

3. Column-based (e.g., Cassandra).

4. Graph-based (e.g., Neo4j).

What is a document-based NoSQL database?

Stores data as JSON documents with flexible fields, making it ideal for dynamic schemas and nested data.

What is a key-value store in NoSQL?

A database that uses a simple key-value pair model, efficient for lookups.

What is a column-based NoSQL database?

Organizes data into column families for efficient storage and retrieval of sparse, dynamic data.

What is a graph database?

Stores data as entities (nodes) and their relationships (edges), ideal for interconnected data.

Why did NoSQL databases become popular?

They addressed scalability and flexibility issues of RDBMS during the rise of web applications, social media, and cloud computing.

What does "horizontal scalability" mean in NoSQL?

Adding more machines to distribute the load, rather than increasing the power of a single machine (vertical scaling).

What is information in IT?

Information is processed or interpreted data that can be organized, manipulated, filtered, or computed to add meaning.

What is the DIKW hierarchy?

A framework where:

1. Data: Raw inputs.

2. Information: Processed data.

3. Knowledge: Application of information.

4. Wisdom: Knowledge rightly applied in a social context.

What is a database?

An organized collection of data managed with a Database Management System (DBMS).