What Is A Bug?

Date First Published: 20th March 2024

Topic: Computer Systems

Subtopic: Computer Software

Article Type: Computer Terms & Definitions

Difficulty: Medium

Difficulty Level: 4/10

CONTENTS

Types Of Bugs
Impact Of Bugs
Ways Of Dealing With Bugs

Learn about what a bug is in this article.

A bug is an unexpected issue in a software program that causes it to behave in an unintended way or crash. They are most often syntax or logic errors within the source code of a program, which can be fixed by a software development tool, known as a debugger.

Types Of Bugs

Different types of bugs can cause programs to malfunction. Below are some of the most common types of computer bugs:

Visual bugs - Something looks wrong with the appearance of the application. For example, there may be a problem with the responsive design of the application that causes it to perform poorly on devices with smaller screens.
Functionality bugs - A program does not work as intended. For example, a user may click on the 'Save' button, but it does not respond when users click on it. More serious bugs may cause the program to freeze or crash due to a memory leak.
Runtime bugs - These cause errors when the program is running. Runtime errors can be caused by a program trying to call a non-existent function.
Arithmetic bugs - These occur due to an integer overflow or underflow and cause an arithmetic operation to result in a numeric value beyond the given range.

Impact Of Bugs

Bugs can be categorised by the impact they have on users. Examples are:

Low-impact bugs - Have little impact on user experience. For example, a typo in the name of the 'Save' function is a low-impact issue because it has no impact on the functionality of the program and users can still do what they need to.
High-impact bugs - Noticeably affect the functionality, but the application is still usable. For example, when the user is in the middle of purchasing goods on an online store and changes their mind, the system may not allow the user to cancel the process before proceeding because the cancel button does not work.
Critical bugs - Interfere with the main functionality of the application and are capable of triggering complete program shutdown. For example, there may be an error within the source code that causes the program to crash every time the user saves something, making it unusable.

Depending on the impact of them, bugs can have a negative impact on the usability of a program and user experience. This is why most programs go through a lot of testing before they are released to the public. Very few programs are completely error-free, even after they have been tested. Even a small typo can lead to a bug. Due to this, software developers often release point updates, (e.g. version 1.0.1), which include fixes for bugs that were found after the software was released.

Ways Of Dealing With Bugs

Software companies and developers use several ways of dealing with bugs. The two methods that are most commonly used include:

Software testers - Software testers check software for bugs. Successful testers can find and remove as many bugs as possible before the software is released to the public.
Bug bounty programs - These offer financial rewards to people for correctly discovering and reporting bugs. Since software bugs can have a great impact on security and productivity, the money is often well spent.