A database is an organized collection of structured information, typically stored electronically in a computer system.
Definition:
- A database consists of:
- Data: Organized into tables, rows, and columns.
- Database Management System (DBMS): Software that manages the data, provides access control, and allows efficient querying.
- Together, the data and the DBMS form a database system.
Common Characteristics:
- Structured Data: Modeled in rows and columns within tables.
- Efficient Access: Data can be easily accessed, modified, and organized.
- Structured Query Language (SQL): Used for writing and querying data.
Evolution of Databases:
- Navigational Databases: Hierarchical and network models (1960s).
- Relational Databases: Popularized in the 1980s.
- Object-Oriented Databases: Emerged in the 1990s.
- NoSQL Databases: Developed for unstructured data and internet-scale applications.
Difference Between Databases and Spreadsheets:
- Databases:
- Hold larger collections of organized information.
- Allow multiple users to securely access and query data.
- Spreadsheets (e.g., Excel):
- Designed for individual users.
- Suitable for simpler data manipulation.
Types of Databases:
- Relational Databases: Use tables with predefined schemas.
- NoSQL Databases: Handle unstructured or semi-structured data.
- Distributed Databases: Span multiple servers or locations.
- Object-Oriented Databases: Store objects directly (e.g., Java objects).
- Graph Databases: Optimize for graph-like data structures.
- Cloud Databases: Hosted in the cloud.