A unit test should just test one method like checking that a sum method returns the sum of two numbers while a feature test can test the functionality of a chain of methods.
Unit test example
/**
* @test
*/
public function name_property_returns_the_authors_last_name_and_first_name()
{
$author = factory(Author::class)->create([
'first_name' => 'Robert',
'last_name' => 'Jordan'
]);
$this->assertEquals('Jordan, Robert', $author->name);
}
Feature test example
/**
* @test
*/
public function when_users_update_a_book_they_are_redirected_to_the_book_index_and_are_shown_a_success_message()
{
$this->createForeignKeys();
$this->signIn();
$book = factory(Book::class)->create();
$book->title = 'Kalle';
$response = $this->patch('/books/' . $book->id, $book->toArray());
$response->assertStatus(302);
$response->assertLocation('/books');
$response = $this->get('/books');
$response->assertSee(e($book->title) . ' successfully updated.');
}