Android Studio pasar entre activitis

public class AcercaDe extends AppCompatActivity {

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

            Button btn2 = (Button) findViewById(R.id.botonact2);
            btn2.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent intent2 = new Intent (v.getContext(), MainActivity.class);
                    startActivityForResult(intent2, 0);
                }
            });
        }
    }