RecyclerView中LinearLayoutManger的用途是什么？

我想知道此代码中LinearLayoutManager类的用途是什么？我只是通过查看android教程来做到这一点的，但并没有解释它！

public class MainActivity extends AppCompatActivity {

    RecyclerView myRecyclerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        myRecyclerView = (RecyclerView)findViewById(R.id.my_recycler_view);

        LinearLayoutManager layoutManager = new LinearLayoutManager(this);//what's the use?
        myRecyclerView.setLayoutManager(layoutManager);

        myRecyclerView.setAdapter(new FriendListAdapter());

    }
}