Fundamentals of Database Systems

Data: Raw facts that have not yet been processed or interpreted.
Information: Processed data that has been organized, structured, or contextualized to make it meaningful and useful.
Metadata: Data about data, describing the attributes, structure, and constraints of the stored information.

Database: An organized collection of related data designed for easy access, management, and updating.
Database Management System (DBMS): Software that allows users to create, manage, retrieve, and update data in a database.
Database System: The complete environment consisting of the database, the DBMS, hardware, software, procedures, and users.
Table: A collection of data organized into rows and columns.
Record: A single, complete set of information within a table (represented as a row).
Field: A specific category of information contained within a record.
Columns: Vertical structures in a table that define the type of information held in each field across records.
Entity: A real-world object, place, person, or concept that is represented in the database.
Relationship: Defines or describes how entities are connected to one another.

Primary Key: A unique identifier assigned to each record in a table to ensure no duplicate rows exist.
Foreign Key: A field in one table that links to the primary key of another table, serving as the field that connects two tables.
Query: A formal request to retrieve, modify, or analyze specific data from a database.
Schema: The overall blueprint or structure of the database system.
Constraint: A rule enforced on data columns to control what data can be stored in the database.
Index: A specialized database structure that speeds up searching and data retrieval operations.

1. Hardware: The physical devices and equipment required to store, process, and run the database system.
2. Software: The operating system, network software, and DBMS software used to operate the database.
3. Data: The actual raw facts, operational material, and metadata stored within the system.
4. Procedures: The documented rules, standards, and guidelines governing how the database system is designed, operated, and maintained.
5. People (Users): The individuals who interact with, design, manage, and maintain the database system.

Database Administrator (DBA): Manages and secures the database, ensuring system availability, performance, and security.
Database Designer: Designs the database structure, defining tables, relationships, schemas, and constraints.
Application Developer: Creates database applications and writes code to interface external software with the database system.
End User: Interacts directly with the system to enter and retrieve data during everyday operations.