CS Computer Science 9618 - Information Representation and Computing Fundamentals (Flashcards)

A comprehensive set of practice questions and answers drawn from the lecture notes on information representation, networks, hardware, software, databases, and security.

What is BCD (Unpacked)?

BCD Unpacked encodes a numeral into one byte (8 bits) with the most-significant bits often insignificant.

What is BCD (Packed)?

BCD Packed encodes a numeral into a nibble (4 bits) and can be two bytes for a full numeral.

What are common applications of BCD?

Digital calculator, digital clock, digital thermometer, and currency values.

Why is ASCII used and what are its limits?

ASCII uses 7 bits (1 byte per character); extended ASCII uses 8 bits and supports up to 256 characters but lacks full international language coverage.

What is Unicode and its main advantage?

Unicode uses 16 or 32 bits and can represent most languages and symbols, offering wide international support.

What is the difference between vector and bitmap images?

Vectors are scalable using mathematical formulas; bitmaps are made of pixels and can become lossy when scaled.

What is a drawing list in vector graphics?

A set of commands that define properties like thickness, style, and color for vector objects.

What is decimation in bitmap images?

Discarding pixels when zooming out, reducing image quality.

What is Bit Streaming?

Transfer of a continuous stream of bits over a network, requiring buffering.

What is sampling rate?

Number of samples taken per second in audio (higher rate means better accuracy).

What is sampling resolution?

Number of bits used for each sample (affects dynamic range and quality).

What is Lossless vs Lossy compression?

Lossless compresses data without loss; lossy discards some data to reduce size.

Give examples of lossless and lossy formats.

Lossless: PNG; Lossy: JPEG and MP3.

What is Run Length Encoding?

A lossless compression method that stores runs of identical data as a single value and count.

What are the main benefits of a Local Area Network (LAN)?

Resource sharing, improved security, lower cost, and centralized file/storage services.

What are common LAN hardware components?

Hubs, switches, NICs, WNICs, WAPs, cables, bridges, and repeaters.

What is a Router?

A device that connects different networks, directs traffic, and assigns IP routing.

What is a Gateway?

A device that connects two networks using different protocols and translates data between them.

What is a WAN?

A Wide Area Network that spans large geographic areas, often using dedicated lines and routers.

What is a DNS?

Domain Name System; translates domain names to IP addresses.

What is a URL?

Uniform Resource Locator; the address used to locate resources on the web, including protocol, domain, and path.

What is HTTP?

Hypertext Transfer Protocol; the protocol used to retrieve linked web resources.

What are the three normal forms in relational databases?

1NF: no repeated groups; 2NF: in 1NF and non-key attributes depend on the primary key; 3NF: in 2NF and all non-key attributes are independent.

What is a Primary Key?

A unique identifier for each row in a table.

What is a Foreign Key?

An attribute that references the primary key of another table.

What is a DBMS?

Database Management System; software that defines, creates, and manipulates databases.

What is DDL vs DML?

DDL defines database structures (CREATE, ALTER); DML manipulates data (SELECT, INSERT, UPDATE, DELETE).

What is SQL used for?

SQL is Structured Query Language used to query and manage relational databases.

What are an IDE’s core components?

Source code editor, compiler/interpreter, run-time environment with debugger, and auto-documenter.

What are the Von Neumann components?

CPU/Processor, memory for data and instructions, input/output devices, and storage; data and instructions stored in the same memory.

What are the main CPU components?

ALU (arithmetic/logic), CU (control unit), System Clock, IAS, and various registers.

What is memory between IAS, MAR, MDR, CIR, PC?

IAS holds data/programs; MAR stores memory addresses; MDR stores data being read/written; CIR holds the current instruction; PC holds the address of the next instruction.

What are the three types of buses used in a computer?

Address Bus (unidirectional), Data Bus (bidirectional), and Control Bus (bidirectional; carries timing/interrupt signals).

What is the effect of bus width on performance?

Wider buses allow more memory addresses and larger word lengths, improving performance.

What is the Fetch-Execute Cycle?

Fetch: PC -> MAR; MDR loads instruction; CIR holds instruction; PC increments. Decode/Execute: instruction is decoded and control signals activate components.

What is the Von Neumann architecture?

Stored-program concept where instructions and data are stored in the same memory and fetched/executed by the CPU.

What is a Buffer in computing?

A temporary storage area used to smooth data transfers between devices or subsystems.

What is an Embedded System?

A microprocessor-based system integrated into a device to control its specific function.

What is a parity check?

A method of detecting errors by adding a parity bit to ensure even or odd parity across data.

What is ARQ?

Automatic Repeat Request; error-control protocol using acknowledgments and timeouts to ensure data integrity.

What are software licensing types?

Commercial (paid with license), Free/Open Source (OSS), Freeware, Shareware.

What is encryption in data security?

Transforming data with keys so that only authorized parties can decipher it.

What is a Digital Signature used for?

A method to verify the sender of a message or data.

What is a Firewall?

A security device/software that filters inbound and outbound network traffic.

What is a DBMS data dictionary?

A repository that stores metadata about database structures, tables, and relationships.

What is a DDL statement?

Data Definition Language statement used to create/modify database structures (CREATE, ALTER, etc.).

What is a DML statement?

Data Manipulation Language statement used to query and modify data (SELECT, INSERT, UPDATE, DELETE).

What is the difference between a 1NF and 2NF database?

1NF requires no repeating groups; 2NF adds dependency requirements where non-key attributes depend on the primary key.