# What is Software Reverse Engineering?

It is the process of reverse-analyzing the code or structure of a ready-made software to understand how it works.

## Overview
It is a detective work performed when you only have a running program and cannot access its source code. By analyzing the binary files of the program, you reveal its logic, security vulnerabilities, or operating principles.

*Analogy: It is like opening up a completed watch and examining how the gears turn to understand how the watch was made.*

## How it works
Using specialized analysis tools (disassembler/decompiler), the machine code of the software is made readable. Then, logical reasoning processes are applied to this code.

## Where it is used
It is used in security research, analyzing competitor software, or modernizing legacy systems.

## Commonly confused with
It should not be confused with writing code; the goal here is not to produce, but to decipher what already exists.

## Frequently asked questions
**Is it legal?**
It is generally accepted for security research, but caution should be exercised regarding copyrights and license agreements.


## Related terms
- [Vulnerability Scanning](/en/dictionary/vulnerability-scanning/)
- [Binary](/en/dictionary/binary/)
- [Security Scanner](/en/dictionary/security-scanner/)

## Related tools
- [Ghidra](/en/discover/ghidra/)

---
Source: TreScout Dictionary · https://trescout.com/en/dictionary/software-reverse-engineering/