The button back in header is different with tow way Resolving Data

 Resolving Data  Form Controller
.state('student.profile', {
			url: '/profile',
			authenticate: true,
			roles: ['student'],
			views: {
				'menuContent': {
					templateUrl: 'modules/students/profile/update/profile-update.html',
					controller: 'StudentProfileUpdateCtrl',
				}},
			resolve: {
				grades: function(gradeService) {
					return gradeService.getByCountry().then(function(data) {
						return data;
					});
				}
			}
		})

Question : Why i used this code . I see button back when i go this state

Resolving Data Form Controller

IF i used this code
.state(‘student.profile’, {
url: ‘/profile’,
authenticate: true,
roles: [‘student’],
views: {
‘menuContent’: {
templateUrl: ‘modules/students/profile/update/profile-update.html’,
controller: ‘StudentProfileUpdateCtrl’,
}}
})

And in my controller i but this code
gradeService.getByCountry().then(function(data) {
$scope.grade = data;
});

I got this button
http://prntscr.com/9fj373 in my header

please help me! I don’t understand the diffrent in 2 case