What is a buffer zone in lockdown 4.0?

Since lockdown 1, there had been red, orange, green and containment zones all over the country. But now there is a buffer zone as well. What is a buffer zone? In this report, you will know all about buffer zones.
Such zones will be the area near containment zones. The district administration will identify the buffer zone. The testing will increase in these areas whereas face masks, social distancing will be of utmost importance.