[angularjs] Difference between onLoad and ng-init in angular

I am learning angular. I don't understand what is difference between onLoad and ng-init for initialization of a variable. In which scope it creates this variable.

For example

<ng-include onLoad="selectedReq=reqSelected" src="'partials/abc.html'"></ng-include>

OR

<ng-include ng-init="selectedReq=reqSelected" src="partials/abc.html"></ng-include>

Please also give me some idea about isolated scope.

From angular's documentation,

ng-init SHOULD NOT be used for any initialization. It should be used only for aliasing. https://docs.angularjs.org/api/ng/directive/ngInit

onload should be used if any expression needs to be evaluated after a partial view is loaded (by ng-include). https://docs.angularjs.org/api/ng/directive/ngInclude

The major difference between them is when used with ng-include.

<div ng-include="partialViewUrl" onload="myFunction()"></div>

In this case, myFunction is called everytime the partial view is loaded.

<div ng-include="partialViewUrl" ng-init="myFunction()"></div>

Whereas, in this case, myFunction is called only once when the parent view is loaded.

Works for me.

<div ng-show="$scope.showme === true">Hello World</div>
<div ng-repeat="a in $scope.bigdata" ng-init="$scope.showme = true">{{ a.title }}</div>