sharepoint online

https://pankajsalunkhesharepointknowledge.wordpress.com/2015/09/30/csom-vs-jsom-vs-ssom-vs-rest-sharepoint/

https://jeremythake.com/sharepoint-apps-playbook-series-part-5-client-side-api-rest-vs-jsom-13d50f9563a5#.19xvb4f8r

http://www.andrewconnell.com/blog/sharepoint-2013-csom-vs.-rest-...-my-preference-and-why

http://www.c-sharpcorner.com/UploadFile/sagarp/csom-vs-jsom-vs-ssom-vs-rest/