Database Theory: Information systems, data and information

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The modern world is completely centered around information.

Companies, big and small, generate a lot of value out of proper information management, and many times that’s their core business.

Most companies could not exist without a proper management of the information they need to operate, in other words their information system.

What is an information system?

An information system is the group of procedures and resources we use to gather, store, process and communicate the information needed in an organization.

What is a computer information system?

A computer information system is the subset of the information system that automates information management using computers.

Inside the computer information system, information is stored as data.

What’s the difference between information and data?

Data is a singular unit of knowledge. It has no intrinsic value on its own. We can’t extract meaning out of it, without knowing more about it.

Information is something that we can link to data, to be able to attach a meaning to it.

Let me make an example. The number 36 is data. Knowing that 36 is my age is information. Information that the data represents my age is essential knowledge that is key in an information system.

Lessons in this unit:

0: Introduction
1: ▶︎ Information systems, data and information
2: Data models
3: What is a Database? And a DBMS?
4: Introduction to the ER Data Model
5: The Relational Model
6: Relational Databases
7: Relational Algebra
8: Introduction to SQL
9: Do you always need a database for your app?