How Laravel, PHP and Composer fit together
PHP runs the application, Laravel supplies the framework and Composer manages its PHP packages. A change to one can affect the others, so an upgrade needs a compatible combination and a working application test.
Planning worksheet
Fictional dependency example
| Part | Illustrative constraint | What to check |
|---|---|---|
| Application | An invented invoicing prototype uses Framework A and PHP Runtime B. No real organization or record is represented. | Read the actual project files before applying any version choice. |
| Package | An invented export package accepts Framework A but excludes the planned Framework C. | Find a supported release, an alternative or a bounded replacement before upgrading. |
| Runtime | The target framework and packages need compatible PHP versions and extensions. | Check the web process, command line, queue workers and scheduled tasks; they may use different runtimes. |
| Release artifact | The reviewed lockfile fixes the selected package versions. | Install that lockfile in the target environment and test the resulting behavior. |
PHP is the runtime
PHP executes the application code. The selected version and installed extensions affect whether Laravel and its packages can run. Hosting control panels may select one PHP version for web requests while the command line or background workers use another.
Check the supported-version information on PHP.net when planning maintenance. Support changes over time; a version that worked at launch may no longer be a suitable target.
Laravel provides shared application features
Laravel supplies facilities such as routing, validation, database access and background jobs. Your application still defines its own permissions and business behavior. A framework upgrade can change assumptions around those features, so review the guide for the actual version transition.
The Laravel release notes describe version support, while the upgrade guide describes a particular transition. Do not assume that one guide covers every older application.
Composer selects and records packages
The composer.json file declares requirements; composer.lock records the resolved package versions. Installing from a reviewed lockfile is different from asking Composer to resolve updates. An update belongs in a controlled development or test environment, followed by review and application tests.
Composer’s basic usage guide explains this distinction. Check platform requirements in the real target environment. Ignoring requirements can hide a mismatch rather than solve it.
Test beyond a successful install
In the fictional example, package compatibility blocks the framework change even if PHP itself is ready. After resolving that blocker, test invoice creation and export with synthetic data, permissions, failed-job handling and retries. The example is an explanation of dependencies, not a tested claim about any named package.
Use the upgrade planner to list unknowns and the release checklist to agree what must pass.