Class Diagram: Definition, Application, and Templates

Last updated on March 19, 2021 by

A class diagram is a type of chart and is part of the Unified Modeling Language. It is primarily used to visualize a system structure. Aside from that, it also shows the major components, its relationship with one another and their respective attributes. As a language in the programming field, class diagrams can be used to translate models into codes. On that note, we will further explain what this diagram is, and its components below.

Ultimate Class Diagram Tutorial

What is Class Diagram?

Due to its appearance, most people mistakes Class diagrams for a flow chart. Although it’s not entirely wrong, there is still a certain distinction between the two. First of all, a uml class diagram is made primarily for developers to help them create a program. This type of diagram helps developers understand the components, flow and attributes of each cases.

Using this information as basis, we can say that class diagrams are synonymous to an architectural blueprint of a building. It contains the essential parts, and every nooks and cranny that a process go through in order for it to be complete. Now you know what is class diagram and its purpose.

Class Diagram Basic Components

Class diagrams consists of the basic elements that a regular UML chart has. However, there are certain elements that you can only find and use on it. That is why, before making one, you must first familiarize yourself with its basic components. On that note, we listed down the main components for a UML class diagram and their purpose or use.

  • Upper section – The most important part of a class diagram because it contains the name of the class, which is basically the topic of the entire chart.
upper class part
  • Middle section – This section contains the attributes and supporting information about the class.
middle section class diagram
  • Bottom section – On this section, you will see the methods or how the class interacts with the information within the system.
uml class diagram
  • Member access modifiers – These are symbols that represent the class of each diagram.

NOTE: Depending on the situation, there may be additional components added to the class diagram. However, the ones above are the most important and should be present on every diagram.

Class Diagram Sample Templates

Software engineering is a stressful job and industry. That is why time is important for developers because it is the main investment in their job. That is why instead of creating their own diagram, most developers or devs as they are called prefer using templates. This way, they will save a lot of time and can work on their actual project earlier that projected. With that being said, we provided some ready-to-use class diagram templates online.

  • ATM System Class Diagram
atm class diagram
Edit this example

Automated Teller Machines or ATMs are one of the most common tools that people use these days. With its capabilities to dispense cash by simply pressing simple buttons, it surely made most of our lives easier. However, as a machine, ATMs follow a strict and sophisticated computer system for security. The template above shows the security process that ATMs follows to comply with their respective banks.

  • Hotel Management System Class Diagram
hotel uml class diagram
Edit this example

Most people mistakes UML class diagram as only applicable for computer systems. However, that is not the case since it is applicable for systems in general. This means that it doesn’t need to be a computer program, as long as it follows a series of interaction and flow. This template for examples shows the relationships in the entire hotel management system.

  • Observer Pattern Class Diagram
observer class diagram
Edit this example

An observer pattern is a design pattern that keeps a list of their clients, and then automatically sends notifications to them if any changes happens within the system. In-general, this is an alert system that monitors and alerts you for any unusual movements.


Class diagrams are usually used for computer programming related tasks. However, the templates above clearly shows that is not the case. Which brings us to the conclusion that it is a useful and versatile type of diagram. On that note, if you want to download such templates, you can visit GitMind, and download various templates, including the ones above for free.

Rating:4.3 /5(based on 23 ratings)Thanks for your rating!
Posted by: on to Tips and Resources. Last updated on March 19, 2021

Leave a Comment

Please input your name!
Please input review content!

Comment (1)

  • I've been a user of GitMind for more than 1 year now, and all I can say is that i have not been disappointed yet. That is why it is highly-recommended.