import {Router, Route} from "react-router-dom"
import Home from "./components/Home/Home"
import Contato from "./components/Contato/Contato"
...
<Router>

    <Route
         path="/home"
         component={Home} />

    <Route
         exact path="/"
         component={Home} />

    <Route
         path="/contato"
         component={Contato} />

</Router>

import {Route, Link} from "react-router-dom";
...

<nav>
    <Link to="/home">Home | </Link>
    <Link to="/sobre">Sobre | </Link>
    <Link to="/contato">Contato | </Link>
    <Link to="/cadastro">Cadastro</Link>
</nav>

import {Redirect} from "react-router-dom"
...

render(){

    if(usuarioLogado){
        return(
            <Redirect to="/paginaUsuario" />
        )
    }
    else{
        return(
            <Redirect to="/login" />
        )
    }

}

import {Router,Route,Switch} from "react-router-dom";
import Home from "./components/Home/Home";
import Contato from "./components/Contato/Contato";
import NotFound from './components/NotFound/NotFound';
...

<Router>
        <Switch>
            <Route path="/home" component={Home} />
            <Route path="/contato" component={Contato} />
            <Route component={NotFound} />
        </Switch>
<Router>