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What is Composer in PHP?
Updated May 24, 2026
Short answer
Composer is a dependency manager for PHP applications.
Deep explanation
Composer installs and manages libraries, resolves dependency versions, and provides autoloading. It uses composer.json and composer.lock for reproducible builds.
Real-world example
Laravel applications use Composer to manage framework packages.
Common mistakes
- Committing the vendor directory instead of using composer install.
Follow-up questions
- What is composer.lock?
- What is autoloading?