Updated: Mar 18, 2019
In SharePoint 2010/2013 On premise, we have timer jobs, which performs repetitive, scheduled tasks. For example, you may need a timer job to fetch Sharepoint list items and send them as reports on daily basis. This timer job can be created as a farm solution and can be deployed in SharePoint 2010/2013 On Premise Server whereas in SharePoint Online, you are not allowed to deploy the farm solutions. To overcome this, you can create Azure WebJobs, which act as scheduled timer jobs for SharePoint Online.