Highlight something on an image

[circatee]

Honestly, am probably overthinking this. With Preview or another app on macOS, how do I merely highlight text or something on the image?
I thought I could do something like this with Preview, no?

Example, I want to email someone an image and simply highlight something on the image.

PS: still newish to macOS, and did this all the time on Windows. So, am probably just missing something obvious.

 

[orionquest]

Use preview mark up tools, you can then draw etc stuff onto the image (arrow, lines, your own text, in various colours) to point out something.
Tools / annotate

 

[bogdanw]

Preview User Guide - Annotate an image in Preview on Mac https://support.apple.com/guide/preview/annotate-an-image-prvw1501/mac

 

[MacGizmo]

For very simple markups/annotation, you can simply select the image in the Finder and hit the Spacebar. A toolbar across the top appears - click the little pen/edit icon. This makes a different toolbar appear which offers several basic editing tools that allow you to annotate the image. See below for a few of the options: