i cloned a git repo and see strange texts in files. HEAD <<< and >>>>>

For example i see code

<<<<<<< HEAD
    public function login()
    {
        if($this->_identity===null) {
            $this->_identity=new UserIdentity($this->username,$this->password);
            $this->_identity->authenticate();
        }
        if($this->_identity->errorCode===UserIdentity::ERROR_NONE) {
=======
    /**
     * Logs in the user using the given username and password in the model.
     * @return boolean whether login is successful
     */
    public function login()
    {
        if($this->_identity===null)
        {
            $this->_identity=new UserIdentity($this->username,$this->password);
            $this->_identity->authenticate();
        }
        if($this->_identity->errorCode===UserIdentity::ERROR_NONE)
        {
>>>>>>> 6f9c开发者_高级运维d42a2926dccc612900c31769a977e71ed261
            $duration=$this->rememberMe ? 3600*24*30 : 0; // 30 days
            Yii::app()->user->login($this->_identity,$duration);
            return true;
        }
<<<<<<< HEAD
        else return false;
=======
        else
        return false;
>>>>>>> 6f9cd42a2926dccc612900c31769a977e71ed261
    }
}

and i didn't know what it means. Can anyone explain ?

---

It's indicating a conflict between different versions.

If you actually see this in a repository that has been cloned then someone has screwed up, because they have committed something which should have been edited (to choose one of the correct bits of code) when they were resolving a merge conflict.