An estimate 7,000 bankers, journalists, treasury ministers and officials and central bankers have flooded into Washington in the past few days for the annual jamboree of the World Bank and the International Monetary Fund. Every two out of three years the city plays host to the joint meetings of the two international agencies. But all year round, every year, this their home.

About 6,800 persons are employed by the two organizations in Washington. The eight buildings that they own (seven for the bank and one for the fund), along with other leased space, occupy about two square blocks downtown, and the IMF's country club covers another 282 acres in Germantown. New buildings for both are planned close to their present downtown locations.

But few Washingtonians know what the two organizations actually do or are supposed to do, how important they are to the local economy, who runs them nor who works for them.

This is not really surprising beaucse members of both organizations tend to think of themselves as international employes accidentally located in Washington and remain somewhat aloof from local life. Tension between Congress and both the bank and the fund over expanding their lending activities has emphasized the distance between the two institutions and their American home.

The names of the two agencies are rather misleading. One of their architects, British economist John Maynard Keynes, remarked that the bank is really more like a fund -- which channels money from rich to poor countries -- while the fund in some ways resembles a bank.

Both were set up by the allied powers at the end of the World War II in an attempt to provide a financial and economic framework for the smooth operation of trade and money transactions between countries. In the words of a World Bank pamphlet, they were supposed to provide "the monetary and financial machinery that would enable nations to work together toward world prosperity."

The Soviet Union was the only one of the 44 nations involved in drawing up the blueprints for the two agencies in Bretton Woods, N.H., that did not join them. Most of the other Eastern bloc countries are also not members, although Romania, Vietnam, Laos and Kampuchea are all members of both the bank and the fund.

The fund's main job is to oversee the working of the international money system and the economic policies of its members countries, in particular as they affect their exchange rates and balance of payments.

It lends money on a short-term basis-for between one and three years -- to member governments who need cash to cover balance-of-payments deficits

The World Bank, which actually consist of three institutions all headed by its president, Robert MacNamara, is supposed to assist the development of its poorer members. The bulk of its work is in lending them long-term money for approved projects such as building a power station, an irrigation system or a hospital that private industry cannot or will not finance.

Typically the bank will be happy with a much longer payoff period of these projects than would private industry, while also taking into account potential benefits to the whole economy rather than just to shareholders.

A country has to join the IMF before it can become a member of the World Bank, so that is cannot benefit from bank loans without also being subject to scrutiny of its general economic policies by the fund. Only five of the 140 countries in the fund have not joined the bank.

The World Bank is much larger than the IMF, with more than 5,000 employes in Washington, compared with the fund's 1,550. This is because while the fund looks just at the braod overall economic policies of its member countries, the bank has to evaluate, approve and check many individual projects in different countries.

The professional staff of both institutions -- which consist mainly of economists byt include engineers, agronomists, nutrition experts, lawyers, and financiers -- are recruited internationally. A stranger wandering into the offices of either would realize immediately that he or she was in an international, and not an American, institution.

But, especially in the past, the United States and other industrialized countries have had more than their fair share of the professional jobs going. Even now the upper echelons of the fund in particular are staffed predominantly by white males from Europe, North America or Australia.

Both agencies now are trying to boost their hirings of women and of nationalities now underrepresented, but they still have a long way to go.

The World Bank's latest annual report boasts that about one-third of its professional staff now comes from developing countries. But only about 27 1/2 percent of senior positions are held by people from the Third World. And despite the drive to hire more women, they still make up only a meager 12 percent of the specialized staff in the bank.

Women make up 23 percent of the fund's professional staff, although little of the top management. About 30 percent of the professionals are from developing countries, with a total of 98 nationalities represented in the fund.

In the bank, professionals account for a little less than half of total employment, while about 56 percent of the fund's staff is composed of professionals.

Other staff, including many of the secretaries and administrators, often -- though by no means always -- are hired from the Washington area.

One thing that many Washingtonians do know about the World Bank and the IMF is that its foreign employes pay no income tax and have salaries and benefits that now look very attractive compared to American scales.

Americans working for the two institutions do pay state and federal income tax and Social Security taxes, but they have their salaries bumped up to allow for this, so that their take-home pay should be the same as that of the foreign colleagues.

Most other countries waive income taxes on their nationals who work for the two organizations. It is quite usual for international agencies such as the Organization for Economic Cooperation and Development in Paris to have similar tax-free salaries.

These agencies are effectively having their salary bills subsidized by the governments who are not collecting income tax. If a Frenchman or an Indian came to work for a private employer in Washington, he or she would have to pay income tax to the U.S. government.

High inflation and a falling dollar hve led to congressional complaints that the bank and fund salaries are too high anyway. They are not far off the midway point between private and public-sector scales that a joint committee of the government representatives on the bank and fund boards have recommended, according to a bank spokesman, but they have kept better pace with inflation than have U.S. government salaries.

Because American salaries have fallen relative to those in parts of Latin America, Europe and Japan, there is much scope for conflict here between politicians and others who think the IMF and bank staff are way over-paid, and the employes themselves, some of whom complain that they could get much more money if they worked for another international agency such as the United Nations or even at home.

They usually resent comparisions with the American federal government because the bank and fund are neither American agencies nor staffed mainly with Americans. Their salaries certainly compare favorably with those of home civil servants in the United States. A mid-career economist in the bank, for example, may be earning $45,000 net of tax, while a department director is paid up to almost $60,000 net of tax. An economist in his or her late 20s just joining the bank would typically be paid between $25,000 and $28,000 net.

Between them the fund and bank pay out about $330 million a year in wages and salaries. Not all of this is pumped into the local economy because many of the staff send part of their salaries home. But a considerable portion goes toward purchases from local stores and businesses just as part of living in the Washington area.

Unlike diplomats, IMF and World Andk employes do have to pay sales tax.

They are also liable for property taxes on the houses that many of them have bought in Washington and its suburbs. So the U.S. government indirectly recieves some revenue from the staff of the two agencies.

Firms in the area, and some further afield, benefit directly from the business created by the running of the organizations themselves. Marriott Corp., which is based in Bethesda, does the catering for both the ban and the fund.The latter will spend about $400,000 on food this year.

The IMF's budget is naturally much smaller at $89 million for the current fiscal year compared with almost $400 million for the World Bank. About 70 percent of the fund's administrative budget is spent in the United States, with the bulk of that going into the Washington area.

Just keeping up the fund bulding is expected to cost $1.9 million this year, with another $1.2 million going to local utility companies.

Both the bank and the fund produce a large volume of documents for internal use, as well as some major publications. The bank's annual report and its World Developement Report are printed locally, as are some of the smaller assignments.The fund will spend about $1.3 million on printing contracts in the coming year, an official said. Washington firms will get roughly half of this business, with the rest going to Baltimore.

The World Bank provides a lot of work for local-based consultants, and also hires consultants from all over the world to work for anything from a few days to several months on particular projects. But in addition to this direct spending -- which came to nearly $24 million in the latest financial year -- the bank last year had about $500 million worth of contracts with consultant firms and think tanks to carry out bank-financed projects for foreign governments.

For example, the Brookings Institution here has done work on bank projects. Legal consultants also are used by the bank to help draw up loan documents.

Two major Washington banks get a lot of business through the bank and fund.

The latter uses Riggs, while there is a branch of American Security on the premises of the World Bank for the use of employes of both organizations. The bank itself deposits its funds with American Security.