Tagged

			<BrowserRouter>
                <div>
                    <div>
                        <ul>
                            <li>
                                <Link to="/Guide/ContactUs">ContactUs</Link>
                            </li>
                        </ul>
                    </div>
                    <Switch>
                        <Route path="/Guide/ContactUs" component={ ContactUs } ></Route>
                        <Route path="/Guide/ContactUs" component={ ContactUs } ></Route>
                    </Switch>
                </div>
            </BrowserRouter>

The result is

Interpretation:

If there are tags, only the first one will be matched in the same path, which can avoid repeated matching.

No label

			<BrowserRouter>
                <div>
                    <div>
                        <ul>
                            <li>
                                <Link to="/Guide/ContactUs">ContactUs</Link>
                            </li>
                        </ul>
                    </div>
                        <Route path="/Guide/ContactUs" component={ ContactUs } ></Route>
                        <Route path="/Guide/ContactUs" component={ ContactUs } ></Route>
                </div>
            </BrowserRouter>

The result is:

Interpretation:
Without labels, all of them will match in the same path. More seriously, it matches the superior path, as shown in the following examples:

<BrowserRouter>
                <div>
                    <div>
                        <ul>
                            <li>
                                <Link to="/Guide/AboutUs">AboutUs</Link>
                            </li>
                        </ul>
                    </div>
                        <Route path="/Guide/ContactUs" component={ ContactUs } ></Route>
                        <Route path="/Guide/ContactUs" component={ ContactUs } ></Route>
                        <Route path="/Guide" component={ AboutUs } ></Route>
                </div>
            </BrowserRouter>

The result is:

Conclusion: In order to better match the rules, we should not abandon them easily.