Explain this with example

Question

HP@LAPTOP-ASEAM8KR MINGW64 ~/Desktop/udemy_laravel/blog

$ php artisan tinker

Psy Shell v0.11.2 (PHP 8.1.4 — cli) by Justin Hileman

$posts = App\Models\Post::create([ 'user_id'=> 0, 'title'=>"this is a cat", 'content'=>"cat is a pet animal" ]);

Illuminate\Database\QueryException with message 'SQLSTATE[HY000]: General error: 1364 Field 'user_id' doesn't have a default value (SQL: insert i

nto posts (title, content, updated_at, created_at) values (this is a cat, cat is a pet animal, 2022-05-11 20:43:23, 2022-05-11 20:43:23

))'

$posts = App\Models\Post::insert([ 'user_id'=> 0, 'title'=>"this is a cat", 'content'=>"cat is a pet animal" ]);

but this command insert the data in the database file post table without add user_id in the fillable property. How can possible? please explain......i am only change after the scope resolution operator insert in the place of create.