CSOM: Client side object model
- CSOM is written in C#
- CSOM runs as an application on a client or as code inside IIS provider
- CSOM calls need to be authenticated (with OAuth)
JSOM: JavaScript object model
- JSOM is written in JavaScript
- JSOM runs in the browser embedded in a html/aspx page
- JSOM calls are automatically authenticated with issues identity since it is JS code running in the browser-

