The largest company in the world by revenue, Walmart, earns about $575 billion per year. That's a lot of money to keep track of. By contrast, the U.S. government spends almost $10 trillion annually if you tally up federal, state, and local budgets.
Clearly, we need a different set of rules and procedures to manage that kind of expenditure effectively. At the same time, administering the various services public spending supports requires a different mindset than that found in business. There's no simple definition of "profit" when you effectively have 330 million shareholders.
This is why public administration is distinct from general management science. Some of the subjects studied are similar, like finance and bookkeeping, economics, personnel administration, and general management. Law and the process by which policies are developed and implemented are also covered. These, of course, are somewhat different in Europe, but most subjects are similar. Public administration degrees from European universities are highly regarded.
A heavy emphasis is placed on skills that are uniquely valuable in the civil service, though. Students will gain the ability to research a number of topics in depth, analyze public policies and their impact, evaluate situations in terms of ethics, and communicate effectively.
Soft skills like these are very important in any bureaucracy and will heavily influence your chances of promotion. Public administration is a common degree choice for people who believe themselves to have leadership potential and wish to make a difference in the world, but lack the inclination (or moral flexibility) to enter politics.