Was ist der Unterschied zwischen model und activeRecord in yii2?

namespace app\models;

use yii\base\Model;

class LoginForm extends Model
{
    public $username;
    public $password;

    public function rules() {
        // 这里写你的验证规则
        [['username', 'password'], 'required'],
        // password is validated by validatePassword()
        ['password', 'checkPassword'], // 验证密码
    }

    // 这里写你验证密码的逻辑
    public function checkPassword($attribute,$params) 
    {
        // ......
    }

    // 这里写登录的逻辑
    public function login()
    {
        // ......
    }
}

namespace app\controllers;
use Yii;
use yii\web\Controller;

class SiteController extends Controller
{
    // ...
    public function actionLogin()
    {
        $model = new LoginForm();
        // 根据用户在登录表单的输入来做判断
        if ($model->load(Yii::$app->request->post()) && $model->login()) {
            return $this->goBack();
        }
    }
}

class ActiveRecord extends BaseActiveRecord
{
...
}

abstract BaseActiveRecord extends Model implements ActiveRecordInterface
{
...
}