What is the difference between data and information?
How does structured data differ from unstructured data?
What is a database, and why is it needed?
Name three database models and describe one briefly.
What are two key differences between the hierarchical and relational database models?
Answers and Descriptions:
Answer: Data is raw, unprocessed facts, while information is data that has been processed, organized, or structured to provide meaning.
Description: Data, such as “25” or “John,” lacks context. Information, like “John is 25 years old,” is meaningful and useful for decision-making. Understanding this distinction helps students appreciate the role of databases in transforming data into actionable information.Answer: Structured data is organized in a fixed format (e.g., tables with rows and columns), while unstructured data lacks a predefined structure (e.g., text, images, videos).
Description: Structured data is easily searchable and manageable in databases (e.g., a table of student records). Unstructured data, like emails or multimedia, is harder to process systematically. This distinction is crucial for choosing appropriate database systems.Answer: A database is an organized collection of data, typically stored and accessed electronically, needed to store, manage, and retrieve data efficiently.
Description: Databases provide a structured way to handle large volumes of data, ensuring quick access, data integrity, and efficient management, which is essential for applications like school records or inventory systems.Answer: Three database models are flat file, hierarchical, and relational. The relational model organizes data into tables with rows and columns, linked by keys.
Description: The relational model, widely used in modern databases like MySQL, allows data to be stored in tables where relationships are established using primary and foreign keys, enabling efficient querying and data integrity.Answer: Hierarchical model organizes data in a tree-like structure with parent-child relationships, while the relational model uses tables with keys. Hierarchical is less flexible for complex relationships compared to relational.
Description: The hierarchical model is rigid, with each child having one parent, suitable for simple structures like file systems. The relational model supports complex queries and relationships, making it more versatile for modern applications.