What is Bug? Definition & Meaning

A bug is an error or flaw in code that causes unexpected behavior — a button that doesn't work, a calculation that returns wrong results, or a page that crashes. In vibe coding, bugs often come from AI misunderstanding your intent, hallucinating APIs, or generating code that works in isolation but breaks in context.

Bugs are inevitable — even in AI-generated code. The difference with vibe coding is that AI can also help you find and fix them.

Types of Bugs

Syntax Bugs

Missing brackets, typos, wrong symbols
Caught by your editor before code runs
AI rarely introduces these

Logic Bugs

Code runs but produces wrong results
Harder to find — requires testing
AI occasionally introduces these

Integration Bugs

Individual pieces work but break together
Common when AI generates code without full context
Often caught during testing

Common AI-Generated Bugs

Hallucinated APIs — Using methods that don't exist
Wrong assumptions — AI assumes a different data structure
Missing edge cases — Works for the common case, breaks on exceptions
Version mismatches — AI uses patterns from an older library version

Debugging Workflow

Reproduce the bug — Can you make it happen consistently?
Read the error message — It often points to the problem
Isolate the cause — Which part of the code is responsible?
Fix and test — Make the change and verify it works
Check for related issues — The same bug pattern might exist elsewhere

AI as Debugging Partner

Paste an error message to AI and describe what you expected. AI is excellent at:

Explaining cryptic error messages
Suggesting fixes based on the error
Identifying patterns that commonly cause specific bugs
Reviewing code for potential issues before they become bugs

Bug

Example