Can you list the main features and functions of Composer?

Composer is a dependency manager for PHP. Its main features and functions include:

• Managing project dependencies: automatic installation, updating, and removal of libraries.
• Autoloading classes for convenient class inclusion without manual require.
• Support for package versioning using semantic versioning.
• Ability to create and publish your own packages.
• Managing dependencies at the project level, allowing libraries to be isolated for each project.

Example of usage:

composer require monolog/monolog

This command adds the Monolog library to the project and updates the composer.json file.