Software Development

Bug

Definition

A software bug is an error, flaw or fault in a computer program or system that causes it to produce an incorrect or unexpected result, or to behave in unintended ways.

Why It Matters

Bugs are an inevitable part of software development. The process of finding and fixing bugs, known as debugging, is a major part of a software engineer's job.

Contextual Example

A user clicks a "Save" button, but their data is not saved and an error message appears. This is a bug. A developer would then need to debug the code to find the cause of the error and fix it.

Common Misunderstandings

  • The term "bug" was famously popularized by Grace Hopper when she found an actual moth stuck in a relay of an early computer, causing it to malfunction.
  • The goal of software testing is to find bugs before they reach the end-user.

Related Terms

Last Updated: December 17, 2025