What is the difference between statutory bonus and PLI based bonus?

Hi All,
Please share the information on below points related to Bonus Act.
1. What is the difference between statutory bonus and PLI based bonus.
2. Also suggest both are mandatory to enforce in organization and what is the calculation criteria.
3. Is there any requirement of records/registers need to maintain.
4. Which are the monthly/Annual returns need to be file.
with regards
Ajay

Dear All,
Our Corporate office located in Gurgaon and register office is at Kolkata.
Also we have four manufacturing units & four Chain Office.
Salaries are processing from corporate office (It is centralized).
Now i have some query related to compliance and annual returns
A) All the statutory returns should be filled from Corporate office or from Retail Office or it should be varies from State to State.
request you kindly confirm the same at earliest.