What is a Seeder in Laravel?

Seeders populate your database with test or initial data. Generate: php artisan make:seeder UserSeeder. The seeder's run() method contains the database insert logic. Run a specific seeder: php artisan db:seed --class=UserSeeder. Run all seeders registered in DatabaseSeeder: php artisan db:seed. Combine with factories: User::factory()->count(50)->create(). Seeders are useful for: populating initial data (admin users, categories, settings), creating test data for development, and resetting the database to a known state. Use php artisan migrate:fresh --seed to rebuild and reseed from scratch.