Why does windows forms text resize itself on different resolutions?

Can anyon tell me why Windows forms text resizes itself on different resolution开发者_开发问答s? This happens often to me and it is frustrating. The font is arial, the form has its default font set to 14.25pt and the labels are 24pt. Why does the form text go over the screen on a smaller resolution, and how can I prevent this?

Ahh I see it's because I set the AutoScaleMode on the form to 'Font' where I should make it DPI or None. Would love a more in depth explanation of how these work as an answer though!