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-