Who are Financial Information Users (FIUs)?

A Financial Information User (FIU) is any regulated entity in the financial services sector, such as banks, lending companies, registered investment advisors, etc., licensed by the RBI, SEBI, IRDAI, or any other regulator who may request your financial data from Financial Information Providers (FIPs) to offer you a financial service.

For example, when you take a loan, the bank offering the loan is an FIU. 

Related question(s):
Who are Financial Information Providers?
How do I register and link my bank account on Account Aggregator?