"Plan-Do-Check-Act" is a continuous quality framework 
based on Dr. Edward Deming's famous rapid 
application "spiral" development model 
for quality through a continuous improvement process to 
promote effective 
testing methods in both structured and unstructured 
environments.

PDCA -  Plan-Do-Check-Act
 This is also called Dieming Wheel(named after Jhon Dieming)
It is cycle which is rep repeated until the product reaches 
to final quality.

Plan- plan the sw product/appilication according to 
requirements
Do- Do according to requirements

Check -check the work whether it is going according to 
       Requirements

Act- Act (correct) the work if there is any deviations from 
the desired requirements.