what is management ?

The term "management" characterizes the process of and/or the personnel leading and directing all or part of an organization (often a business) through the deployment and manipulation of resources (human, capital, intellectual or intangible).
According to the Oxford English Dictionary, the word "manage" comes from the Italian maneggiare (to handle — especially a horse), which in turn derives from the Latin manus (hand). The French word mesnagement (later ménagement) influenced the development in meaning of the English word management in the 17th and 18th centuries.
Management operates through various functions, often classified as planning, organizing, leading/motivating and controlling.

Planning: deciding what has to happen in the future (today, next week, next month, next year, over the next five years, etc.) and generating plans for action.
Organizing: making optimum use of the resources required to enable the successful carrying out of plans.
Leading/Motivating: exhibiting skills in these areas for getting others to play an effective part in achieving plans.
Controlling: monitoring — checking progress against plans, which may need modification based on feedback
Mary Parker Follett (1868–1933), who wrote on the topic in the early twentieth-century, defined management as "the art of getting things done through people". [1] One can also think of management functionally, as the action of measuring a quantity on a regular basis and of adjusting some initial plan; or as the actions taken to reach one's intended goal. This applies even in situations where planning does not take place. From this perspective, Frenchman Henri Fayol [2] considers management consists of five functions:
1. planning

2. organizing

3. leading

4. co-ordinating

5. controlling
Some people, however, find this definition, while useful, far too narrow. The phrase "management is what managers do" occurs widely, suggesting the difficulty of defining management, the shifting nature of definitions, and the connection of managerial practices with the existence of a managerial cadre or class.
One habit of thought regards management as equivalent to "business administration", although this then excludes management in places outside commerce, as for example in charities and in the public sector. Nonetheless, university departments which teach management usually get called "business schools".
Speakers of English may also use the term "management" or "the management" as a collective word describing the managers of an organization, for example of a corporation.

In for-profit work, management has as its primary function the satisfaction of a range of stakeholders. This typically involves making a profit (for the shareholders), creating valued products at a reasonable cost (for customers), and providing rewarding employment opportunities (for employees). In nonprofit management, add the importance of keeping the faith of donors. In most models of management/governance, shareholders vote for the board of directors, and the board then hires senior management. Some organizations have experimented with other methods (such as employee-voting models) of selecting or reviewing managers; but this occurs only very rarely.
In the public sector of countries constituted as representative democracies, voters elect politicians to public office. Such politicians hire many managers and administrators, and in some countries like the United States political appointees lose their jobs on the election of a new president/governor/mayor. Some 2500 people serve at the pleasure of the United States Chief Executive, including all of the top US government executives.

Definition of management :
Management is the process of getting things done, effectively and efficiently, through and with other people
(Management 係一個過程把有效率和有效能地把事情做好)

Definition of efficiency:
Means doing the task correctly; refers to the relationship between inputs and outputs; seeks to minimize resource costs.
(Efficiency 係一種方法把input and output 的成本變到最小把工作做正確....)

Definition of effectiveness:
Means doing the right tasks, goals attainment