GSTR 9 and 9a

for  both 9 & 9A  last date is 31/12/2018

GSTR 9 IS  AN ANNUAL RETURN FORM, THOSE TURNOVER LESS THAN 2 CRORE THEY CAN FILED BEFORE 31.12.2018.

FOR 2 CR ABOVE THEY CAN FILED 9C WITH THE HELP OF CA,CS,CMA.

GSTR 9A – GSTR 9A should be filed by the persons registered under composition scheme under GST.

 What is composition return perfoma Please tell me?