Computer Science

What is HTML?

HTML (HyperText Markup Language) is the standard markup language for creating web pages and web applications. It uses a structure of elements to define the content of a page.

What is CSS?

CSS (Cascading Style Sheets) is a style sheet language used for describing the presentation of a document written in HTML or XML. It controls the layout, colors, fonts, and overall visual appearance of web pages.

What are the core components of an HTML document structure?

An HTML document typically includes:

1. : Declaration defining the document type.

2. : The root element of all HTML pages.

3. : Contains meta-information about the HTML document (e.g., title, character set).

4. : Contains the visible page content.

Explain the box model in CSS.

The CSS box model describes how HTML elements are rendered rectangular boxes. It consists of:

• Content: The actual content of the box, where text and images appear.

• Padding: Clears an area around the content, inside the border.

• Border: A border that goes around the padding and content.

• Margin: Clears an area outside the border, making space between elements.

User Interface Design

What is User Interface (UI) Design?

UI Design focuses on the visual and interactive elements of a product that users interact with. It aims to make interfaces aesthetically pleasing and intuitive, ensuring the product is easy to use and provides a positive user experience.

List key principles of good UI design.

1. Consistency: Maintain uniform design elements and behavior.

2. Clarity: Ensure elements are understandable and unambiguous.

3. Feedback: Provide immediate responses to user actions.

4. Efficiency: Minimize user effort and steps.

5. Forgiveness: Allow users to recover from errors easily.

6. Accessibility: Design for users with diverse abilities.

What is the difference between UI and UX?

UI (User Interface) focuses on the presentation and interactivity of a product (how it looks and feels). UX (User Experience) encompasses the entire experience a user has with a product, including its usability, accessibility, and overall satisfaction.

Explain the concept of 'affordance' in UI design.

Affordance refers to the properties of an object that suggest how it can be used. In UI, it's about designing elements (e.g., buttons that look clickable, sliders that look draggable) in a way that their function is immediately obvious to the user without explicit instructions.

What is a Text-based User Interface (TUI)?

A Text-based User Interface (TUI) is a type of user interface where interaction is solely through text commands and responses. Users type commands, and the system displays text output. Examples include command-line interfaces (CLIs).

What is a Form-based User Interface?

A Form-based User Interface (FUI) presents information and input fields in structured forms for users to fill out. It's commonly used for data entry, registration, or application processes, guiding users through specific inputs.

What is a Menu-based User Interface?

A Menu-based User Interface (MUI) provides users with a list of options or commands to choose from. Users interact by selecting items from menus, making navigation and command execution straightforward and reducing the need to remember specific commands.

What is a Graphical User Interface (GUI)?

A Graphical User Interface (GUI) allows users to interact with electronic devices through graphical icons, visual indicators, and secondary notation instead of text-based commands. It uses elements like windows, icons, menus, and pointers (WIMP).

What is a Sensor-based User Interface?

A Sensor-based User Interface (SUI) utilizes sensor data (e.g., accelerometers, gyroscopes, biometric sensors, GPS) to enable user interaction. Actions are triggered by physical movements, environmental changes, or biometric inputs rather than traditional input devices.

What is a Speech-based User Interface (SUI)?

A Speech-based User Interface (SUI) allows users to interact with a system using spoken commands. It processes natural language input (voice recognition) and often provides audio feedback. Examples include virtual assistants like Siri or Alexa.

Tablet Computer Features

A computer network is a group of interconnected computing devices (e.g., computers, servers, printers) that can exchange data and share resources with each other over a communication link.

What is a tablet computer?

A tablet computer is a portable computing device that is typically larger than a smartphone and smaller than a laptop, featuring a touchscreen display as its primary input method, often without a physical keyboard or mouse.

List common features of tablet computers.

1. Touchscreen Interface: Multi-touch display for navigation and input.

2. Portability: Lightweight and thin design.

3. Operating Systems: Typically optimized mobile OS (e.g., iOS, Android, Windows).

4. Wireless Connectivity: Wi-Fi, Bluetooth, often cellular data (4G/5G).

5. Cameras: Front and rear-facing cameras for photos, videos, and video calls.

6. Sensors: Accelerometer, gyroscope, ambient light sensor, GPS.

7. Battery Life: Designed for extended use on a single charge.

What distinguishes tablets from laptops?

Tablets typically prioritize portability, touch input, and a consumption-focused user experience, often running mobile operating systems. Laptops usually offer more processing power, physical keyboards, and run full desktop operating systems, geared towards productivity.

How do tablets handle data input and output?

Input is primarily through the touchscreen (gestures, virtual keyboard) and voice. Output is primarily to the display and built-in speakers, with options for external displays via ports or wireless casting.

Computer Networks

A network switch is a device that connects multiple computers and other network devices within a LAN. It uses packet switching to receive, process, and forward data to the specific device it is intended for, improving network efficiency compared to a hub.

What is a computer network?

A computer network is a group of interconnected computing devices (e.g., computers, servers, printers) that can exchange data and share resources with each other over a communication link.

What are the main types of computer networks?

1. LAN (Local Area Network): Connects devices in a small geographic area (e.g., home, office).

2. WAN (Wide Area Network): Connects devices over a large geographic area (e.g., cities, countries), often using public telecommunication lines.

3. MAN (Metropolitan Area Network): Covers a larger area than a LAN but smaller than a WAN (e.g., a city).

4. PAN (Personal Area Network): Connects devices within a personal workspace (e.g., Bluetooth devices).

List common network topologies.

1. Bus Topology: All devices are connected to a single central cable (bus).

2. Star Topology: All devices are connected to a central hub or switch.

3. Ring Topology: Devices are connected in a closed loop, where data travels in one direction.

4. Mesh Topology: Every device is connected to every other device.

5. Tree Topology: A hierarchical structure combining characteristics of bus and star topologies.

What is a network protocol?

A network protocol is a set of rules and standards that governs how data is transmitted and received between devices in a network, ensuring successful communication (e.g., TCP/IP, HTTP, FTP).

Explain the role of a router in a network.

A router is a networking device that forwards data packets between computer networks. It directs traffic by determining the best path for data to travel across different networks, enabling communication between them (e.g., connecting a home LAN to the internet).

What is a network switch?

A network switch is a device that connects multiple computers and other network devices within a LAN. It uses packet switching to receive, process, and forward data to the specific device it is intended for, improving network efficiency compared to a hub.

Differentiate between client-server and peer-to-peer network models.

1. Client-Server: Centralized model where clients request services from a powerful central server. Servers manage resources and provide services to multiple clients.

2. Peer-to-Peer (P2P): Decentralized model where all connected devices (peers) have equal capabilities and can act as both clients and servers, sharing resources directly with each other.

What is the OSI model?

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven abstract layers, from the physical layer to the application layer, to facilitate interoperability.

Types of Servers

What is a File Server?

A File Server is a computer on a network that provides a central location for users to store, manage, share, and access files and data. It allows multiple users to work on the same shared files and ensures data security and backups.

What is a Mail Server?

A Mail Server is a computer system that sends and receives email messages. It stores incoming mail for distribution to local users and forwards outgoing mail to other mail servers, using protocols like SMTP, POP3, and IMAP.

What is an Application Server?

An Application Server is a software framework that provides an environment for running specific applications. It manages business logic, data access, and provides services for client applications, often handling complex, dynamic applications.

What is a Web Server?

A Web Server is a computer program that stores website content (like HTML pages, images, and videos) and delivers web pages to client web browsers upon request using HTTP. It processes HTTP requests and serves web content.

What is a Print Server?

A Print Server is a device or software that connects printers to client computers over a network. It manages print jobs, queues them, and sends them to the appropriate printer, allowing multiple users to share a single printer or a set of printers.

Internet Technologies

A spreadsheet is an interactive computer application for organizing, analyzing, and storing data in tabular form, consisting of rows and columns. Cells within the table can contain numbers, text, or formulas.

What is the Internet?

The Internet is a global system of interconnected computer networks that uses the standard Internet Protocol Suite (TCP/IP) to link billions of devices worldwide. It hosts a vast range of information and communication resources.

Briefly describe how a web page loads in a browser.

1. DNS Lookup: Browser resolves domain name (e.g., example.com) to an IP address.
2. TCP Connection: Browser establishes a TCP connection with the web server.
3. HTTP Request: Browser sends an HTTP request for the web page.
4. HTTP Response: Server sends back the HTML, CSS, JavaScript, and other resources.
5. Rendering: Browser parses and renders the content to display the page.

What is a DNS server?

A DNS (Domain Name System) server translates human-readable domain names (like example.com) into machine-readable IP addresses (like 192.0.2.1). It acts like a phonebook for the internet.

Explain the role of HTTP and HTTPS.

1. HTTP (Hypertext Transfer Protocol): The foundation of data communication for the World Wide Web, used for transmitting hypertext over the internet.
2. HTTPS (Hypertext Transfer Protocol Secure): An encrypted version of HTTP, ensuring secure communication between a web browser and a server by using SSL/TLS encryption.

What is an IP address?

An IP (Internet Protocol) address is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It identifies the device and specifies its location on the network.

Automatic and Manual Data Input and Output

A spreadsheet is an interactive computer application for organizing, analyzing, and storing data in tabular form, consisting of rows and columns. Cells within the table can contain numbers, text, or formulas.

What is manual data input?

Manual data input involves a human operator physically entering data into a computer system using input devices like keyboards, mice, touchscreens, or barcode scanners. It's often slower and more prone to human error but flexible.

What is automatic data input?

Automatic data input involves systems or devices capturing data without direct human intervention. Examples include sensors, RFID readers, OCR (Optical Character Recognition) from scanned documents, and data streaming from connected devices (IoT).

Give examples of manual data output.

1. Printed Reports: Information output onto paper.
2. Screen Display: Information presented on a monitor or screen for human viewing.
3. Sound/Audio: Alerts, voice output played through speakers.
4. Physical Controls: Actuators or indicators that humans respond to.

Give examples of automatic data output.

1. Control Signals: Data sent to machines to control processes (e.g., turning a motor on/off).
2. Data Logging: Data automatically written to files or databases for later analysis.
3. Network Transmission: Data sent over a network to another system or device.
4. Alarms/Alerts: Automated notifications triggered by specific conditions.

Data Processing Using Spreadsheets

A	B	A OR B

What is a spreadsheet?

A spreadsheet is an interactive computer application for organizing, analyzing, and storing data in tabular form, consisting of rows and columns. Cells within the table can contain numbers, text, or formulas.

How are formulas used in spreadsheets for data processing?

Formulas are expressions that perform calculations on values in a spreadsheet. They begin with an equals sign (=) and can include cell references, arithmetic operators (+, -, \\*, /), and functions to automate calculations and manipulate data.

Name common functions used for data processing in spreadsheets.

1. SUM(): Adds a range of numbers.
2. AVERAGE(): Calculates the mean of a range of numbers.
3. COUNT(): Counts the number of cells containing numbers.
4. MAX()/MIN(): Finds the largest/smallest value in a range.
5. IF(): Performs conditional logic.
6. VLOOKUP()/HLOOKUP(): Searches for values in tables.

How can sorting and filtering aid data processing in spreadsheets?

1. Sorting: Arranges data in ascending or descending order based on one or more columns, making it easier to find specific data or identify patterns.
2. Filtering: Displays only the rows that meet specific criteria, hiding irrelevant data and allowing focus on a subset of information.

Explain how charts can be used for data analysis in spreadsheets.

Charts (e.g., bar charts, pie charts, line graphs) visualize data, making complex numerical information easier to understand and interpret. They help identify trends, patterns, and relationships that might not be obvious from raw data, aiding in data analysis and decision-making.

Algorithms and Boolean Logic

A	B	A OR B

What is an algorithm?

An algorithm is a finite set of well-defined, ordered instructions for performing a task or calculation, typically used to solve a specific problem or class of problems. It must be unambiguous and terminate after a finite number of steps.

What are common ways to represent algorithms?

1. Pseudocode: A high-level description of an algorithm using a mix of natural language and programming constructs, independent of any specific programming language.
2. Flowcharts: Visual diagrams that use standard symbols to represent the steps and decision points in an algorithm, showing the flow of control.

What is Boolean Logic?

Boolean Logic is a branch of algebra in which the values of variables can only be 'true' or 'false' (or 1 or 0). It's fundamental to computer science as it forms the basis for digital circuit design and logical operations in programming.

Explain the three basic Boolean operators: AND, OR, NOT.

1. AND: The result is 'true' only if all inputs are 'true'. (e.g., A AND B is true only if A is true AND B is true).

2. OR: The result is 'true' if at least one input is 'true'. (e.g., A OR B is true if A is true OR B is true or both are true).

3. NOT: Inverts the input. If the input is 'true', NOT makes it 'false', and vice versa. (e.g., NOT A is true if A is false).

Construct a truth table for A AND B.

Construct