You
You park ₹1 lakh in savings
Bank pays you:about 3% a year
The bank
Takes deposits in.
Lends money out.
Lends money out.
A borrower
Someone's home loan, car loan, business loan
Bank charges them:about 9% a year
the 6% gap
That gap, times crores of accounts, is the bank's engine.
Minus salaries, branches, and loans that go bad.