The difference in behavior between Eloquent's first() method and the DB facade's first() method lies in the type of object they return.
When using Eloquent, like User::where('email', $email)->first(), it creates an instance of the User model class with mapped properties from the database. So, $user is an object of the User class, allowing access like $user['id'].
On the other hand, using the DB facade like DB::table('users')->where('email', $email)->first() returns a generic PHP object without specific structure or methods. Hence, accessing $user['id'] throws an error because it lacks the model's property structure. It might have the id property, but you need to access it through its actual name, like $user->id.
In most cases, Eloquent is preferred due to its readability, type safety, and seamless relationship handling. Use the DB facade only for specific raw SQL queries or when dealing with tables without corresponding models.
I hope this will help!