IT Chapter 10&11

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Stores characters, letters, and numbers; suitable for non-numeric data such as names and addresses.

Alphanumeric

A mix of letters and numbers; useful for product codes or mixed data like license plate numbers.

Integer

A data type that stores whole numbers only (e.g., age, count of items).

Decimal

A data type that stores fractional numbers (e.g., price, temperature readings).

Date & Time

A datatype that stores date and time values for scheduling and timestamps.

Boolean

A datatype that stores True/False or Yes/No values, used in decision-making fields.

Primary Key

A unique identifier for a record (e.g., Student ID).

Foreign Key

A field in one table that links to the primary key in another table to maintain relationships.

Composite Key

Two or more fields combined to form a unique identifier (e.g., Course ID + Student ID).

Referential Integrity

Ensures that foreign key values always reference a valid primary key to maintain data consistency.

Flat File Database

A single table storing all data, leading to redundancy and inefficiency.

Relational Database

Multiple linked tables that reduce redundancy and improve efficiency.

Entity Relationship Diagrams (ERD)

Diagrams used to represent the relationships between entities in a database.

Validation

Ensures the correct data format using rules such as range checks, presence checks, and input masks.

Verification

Confirms correctness via double entry or proofreading.

Static Queries

Pre-defined queries that retrieve fixed results.

Dynamic Queries

Queries that adjust criteria based on user input.

Normalisation to 3NF

A process to reduce redundancy and improve efficiency in a database.

Unnormalized Form (UNF)

Data stored with redundancy.

First Normal Form (1NF)

Eliminates repeating groups and ensures unique rows.

Second Normal Form (2NF)

Removes partial dependencies where each attribute must depend on the whole primary key.

Third Normal Form (3NF)

Removes transitive dependencies where non-key fields should not depend on other non-key fields.

File Access Methods

Techniques such as Sequential, Indexed Sequential, and Direct Access for reading data.

Database Management Systems (DBMS)

Software that allows the management of databases, including hierarchical, network, object-oriented, and relational models.

Aspect Ratio

The ratio of the width to the height of a video frame.

Trimming

Removing unwanted parts of a video.

Splicing

Merging multiple video clips into one.

Fading

Smooth transitions in video or audio editing.

Compression Methods

Techniques to reduce file size, categorized as lossy or lossless.

MP3

A compressed audio file format widely used for music.

WAV

An uncompressed audio format that retains high-quality sound.