> [!INFO]+ What is Dewey Decimal System? > The Dewey Decimal System is a way to put books in order by subject. It is often used in public libraries and schools in the United States and other countries. [It places the books on the shelf by subject using numbers from 000 to 999](https://simple.wikipedia.org/wiki/Dewey_Decimal_System). Each number represents a specific topic or discipline, and can be further divided into decimal points for more detail. [For example, 500 is the main class for natural sciences and mathematics, 510 is the subclass for mathematics, and 512 is the sub-subclass for algebra](https://simple.wikipedia.org/wiki/Dewey_Decimal_System) > > In the *context of personal note taking*, this system assigns a numerical code to each subject or topic, and allows for further subdivisions using decimal points. [For example, the code 004.6 represents the subject of computer networks, and the code 004.67 represents the subtopic of wireless networks](https://johnnydecimal.com/) > >*Source:* Bing ChatGPT There is another system called [[Johnny Decimal System]], that is a variation of the [[Dewey Decimal System]] and [modified by keeping the context of digital note taking in mind](https://www.reddit.com/r/ObsidianMD/comments/131hb6i/comment/ji0rgkz/). The significance of these systems is that they help to organize information in a logical and consistent way, making it easier to find and access when needed. They also help to avoid duplication, confusion, and clutter in the information space. By using these systems, one can create a clear structure and hierarchy for their notes and knowledge, and improve their productivity and efficiency. - [[Difference between Dewey Decimal System & Johnny Decimal System]]