Investment banking
They do not except deposits from people.
An investment bank helps companies or individuals to raise capital/money by issuing securities like bonds or equities.
An investment bank may also help in mergers and acquisitions.
They help in trading of derivatives, equities, currencies and commodities.
Two main lines/sides of investment banking – Sell side and buy side. Buy side example hedge funds buy derivatives from banks (sell side). Banks are sell side and hedge funds are buy sides.
Merchant Banking
Instead of giving loan to the company they buy shares in it.
OTCWIRE 