What is the technology used in the phones which reduces blur in the photos even if they are zoomed? What is the technology used in the phones which reduces blur in the photos even if they are zoomed?

In our old mobile phones, our phone camera pictures used to look blurred when the are zoomed. But now, it is not the case. Which technology is responsible for the reduced blur?
Are you referring to autofocus?


  An autofocus (or AF) optical system uses a sensor, a control system
  and a motor to focus fully automatic or on a manually selected point
  or area.