I can see sometimes people just use browserHistory as history, like

import {Router, Route, IndexRoute, browserHistory} from 'react-router'
const router = (
    <Provider store={store}>
        <Router history={browserHistory}>
            <Route path="/" component={App}></Route>
        </Router>
    </Provider>
)

but in some projects, people are using syncHistoryWithStore, like

const history = syncHistoryWithStore(browserHistory, store)

render(
  <Root store={store} history={history} />,
  document.getElementById('root')
)

when should I use the latter? why syncHistoryWithStore is needed?

thanks