A large international bank like DeutscheBank operates in many different business areas. Basically, they can be broken down into six main areas: 1. Retail ba

A large international bank like DeutscheBank operates in many different business areas. Basically, they can be broken down into six main areas: 1. Retail banking 2. Commercial banking 3. Investment banking 4. Investment/money management services 5. Proprietary trading 6. Other random financial things Retail banking is mostly what you're thinking of for your community bank. That is consumer deposits and loans (for cars, houses, etc). And possibly small business loans, lines of credit, etc. (though at some banks, these are part of commercial banking instead). These things are typically handled at the local branch level. Commercial banking is for larger corporate customers. The bank generally offers more services in addition to deposits and lines of credit. They may include loans, foreign exchange, treasury services (cash management), payment services, etc. Investment banking is sort of related to commercial banking. Generally speaking, it revolves around arranging financing (rather than providing it as commercial bankers would do). It includes things like bond issuences, mergers & acquisitions, private equity deals, etc. Investment/money management services may include an actual brokerage operation, custody services, and high-net-worth money management/investment advisers. Services range from do-it-yourself-online to we-handle-everything-for-you-so-you-don't-have-to-think-about-it. Part of this will often be the production of analyst reports and market forecasts, though this is sometimes outsourced. Proprietary trading is where the bank uses its own money to trade or invest in various securities. This is distinct from investment services in that they do not use client money and thus must be segregated into a different group by law. Finally, there are a slew of random financial services that some banks do and some banks don't. In terms of size, they can be very large (or even dominate) to a rounding error on their books. Everything from trust accounts to credit card issuance, from tax prep to reselling insurance. And really finally, there are a number of internal groups that are specific to banks. Two that come to mind are compliance and risk management. IT often also has quite a large headcount (though often spread out in different business units). Each bank organizes itself somewhat differently so take what I wrote with a grain of salt. Sometimes the same product may even fall under different departments in different countries because of regulatory issues.