how to have different displays on macbook air and external monitor

Nojniles wrote:

I have a macbook air and one external monitor. Is it possible to have different displays on each one? I can do it on my office pc, but I have tech support for that.

Check these instructions and use extended display mode.

Use an external display with your MacBook Air - Apple Support

There are a couple of ways of doing this:

• Using extended desktop mode with "Displays have separate Spaces" disabled. The two displays will then show you different parts of the same virtual desktop ("Space").
• Using "Displays have separate Spaces" (so each display has its own dedicated virtual desktop)

Extend or mirror your Mac desktop across multiple displays - Apple Support

Work in multiple spaces on Mac - Apple Support