A multi-layered system of networks and capacities linked together with a common factor, money! The banking industry has existed for years and in its modern capacity is an integral part of global business.

The Banking Industry *Image credit: Shutterstock, Inc Copyright: isak55 

The Banking Industry *Image credit: Shutterstock, Inc Copyright: isak55
The banking sector can be broken down into number of sectors, however some banks (like a business) pursue different avenues that others may chose not to. It is the business of managing financial assets and commodities along with the risk associated with that management. As complicated as that sounds, the best way to look at a bank is as a business. And just like any other business, a bank is in the business of making money.
Different banking sectors:
A number of global banking operations are often termed differently but they essentially do the same thing. This means the terminology could vary from bank to bank.

Commercial Banking, Global Banking, Investments and Markets - from dealing with multinational banking deals/structuring, trading along with mergers and acquisitions. This is a big part of the global banking arena.

Business, Private, Retail and Wealth Management – varies from dealing with businesses to individuals, promoting relevant banking products/solutions and structuring loans and investments.

Operations and Enabling Functions – this is the support roles that are set in place to make the bank work efficiently.

Within these sectors are various specialised areas from lending to risk management. There are even fraud specialists, IT Support roles, marketing and human resources, to name but a few. The key is to look at a bank as a beehive of sorts. Further there are some banks which will only do specific areas of banking, i.e. investment banking, mortgages etc. In these cases each bank becomes a business system of its own and is broken down into various divisions. For example, an investment bank can be described structurally as having a front office, a middle office and a back office.
3 Popular Careers in banks:
Retail Banker – dealing with individuals/entities and their banking needs. This includes the marketing, introduction and setting up of banking products with a banking client.

Trader – an individual who is responsible for raising capital through the transferring of financial assets for a bank.  

Analyst – an individual who is responsible for the evaluation of investments.  
(Reference - investopedia.com)
Employment within the bank:
Each bank will have its own specific employment requirements. Look at the specific bank that you wish to work for and research their relevant job or employment areas.
Find out more about the best of the best in the banking sector from the following:
Accuity bank rankings 
Banking for the world:
The International Monetary Fund (IMF)  
The World Bank
The movies:
The cautionary tale - Rogue Trader – it’s about not what to do in a banking career!
Check out - Films and Television shows that inspire a career in the Financial Sector on FirstStep.me