1、路由经过中间件方面不同

打开kerenl.php就可以看到区别

    protected $middlewareGroups = [
'web' => [
\App\Http\Middleware\EncryptCookies::class,
\Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
\Illuminate\Session\Middleware\StartSession::class,
// \Illuminate\Session\Middleware\AuthenticateSession::class,
\Illuminate\View\Middleware\ShareErrorsFromSession::class,
\App\Http\Middleware\VerifyCsrfToken::class,
\Illuminate\Routing\Middleware\SubstituteBindings::class,
],

'api' => [
'throttle:60,1',
'bindings',
],
];
2、路径不一样

在web.php写的路由是这样的

eg:http://quan.cms/backend/admin/add

在api.php写的路由需要加上XXX/api/路由地址,相当于在web.php的基础上加了一层api

eg:http://quan.cms/api/backend/admin/add