The International Olympic Committee, which owns the Olympic Games and oversees their conduct, has been characterized variously as an "exclusive men's club," "the world's most powerful sports institution" and "the best modern example of a self-perpetuating oligarchy."

All three descriptions are apt. Structually and operationally unfathomable to the uninitiated, the IOC also is widely misunderstood. Few people outside the immediate Olympic family ever grasp what it is, how it works, or where it derives its considerable authority.

"A big part of the problem with the Olympics is that the IOC is a law unto itself, and people around here are just beginning to understand how it operates," mused a White House aide working on a U.S. proposal that the 1980 Summer Games be moved from Moscow, postponed or canceled in response to the Soviet invasion of Afghanistan -- a presentation that the IOC will consider during three days of critical meetings here, beginning Saturday evening.

"We're accustomed to dealing with all kinds of governments and institutions," President Carter's man said, "but we've never come across one quite like this."

The IOC often has been criticized as an anachronism, made up of dreamers and schemers and senile old men of means who can afford to believe that serious sport should still be the province of amateurs.

But those who lambaste the IOC as being hopelessly insulated from reality have difficulty explaining how this international "old school tie" network of well-heeled fuddyduddies managed to guide their quadrennial Winter and Summer Games to their present stature as the most spectacular and revered of sports extravaganzas.

According to its charter, the IOC chooses its own members -- there are 89 at the moment, the highest number ever -- and is autonomous and answerable only to the charter as interpreted by the group's collective conscience.

Independence from government interference and political pressures was the cornerstone of its design by the French Baron Pierre de Coubertin, who in 1894 articulated his grand vision of reviving the ancient Greek Olympics, and founded the IOC to oversee the resurrection.

Geoffrey Miller, the European sports editor of the Associated Press and an old hand at covering IOC proceedings, has provided perhaps the most illuminating look to date at the IOC and its modus operandi in his recent book, "Behind the Olympic Rings" (H. O. Zimman Inc., 1979).

He recalls that Lord Killanin, the IOC president since 1972, once confronted a criticism of the IOC's fundamentally undemocratic nature by saying: "That is the usual way with a board of trustees."

This is essentially the way most IOC members regard themselves: as trustees of the letter and spirit of the Olympic charter. And that is the best way to think of them as a group: as a private board of trustees -- crusty, selfrighteous, fiercely independent and arrogant -- charged with the task and obligation of upholding their idealistic charter.

Legally, the IOC was created by the Congress of Paris on June 23, 1894, and "entrusted with the control and development of the modern Olympic Games."

According to its charter, the IOC is a nonprofit "body corporate by international law having judicial status and perpetual succession."

Its headquarters are at the Chateau de Vidy in Lausanne, Switzerland, where a $3-million-per-year secretariat, under the executive supervision of Madame Monique Berlioux, carries out the day-to-day operations authorized by the full IOC membership.

The members meet in a General Assembly, also called a "session," once a year, and twice in Olympic years -- immediately before the Winter and Summer Games.

The IOC also has an elaborate committee structure, including an Executive Board comprised of the president (who serves an eight-year term and is eligible for reelection to successive four-year terms), three vice presidents, and five other members.

The Executive Board meets approximately three times a year, and frequently is authorized to conduct business on behalf of the IOC. In turn, it often delegates administrative decisions to the president and the capable Mme. Berlioux, the woman executive director of an organization that has never had a woman member.

Crucial policy decisions however, are always left to the full IOC session, made up of members hand-picked by the Executive Board and approved by the membership. By custom there is never more than one IOC member from any country except a nation that has hosted an Olympic Games, the most important countries in international sport and certain others, which may have two members.

Until 1964, members served for life, and any members elected before that year can serve as long as they wish. Members elected since 1964 are obliged to retire at age 72.

The charter stipulates that the IOC "selects such persons as it considers qualified to be members, provided that they speak French or English [the languages in which all IOC document are issued] and reside in a country which has a National Olympic Committee recognized by the IOC."

But it makes clear that "members of the IOC are representatives of the IOC in their countries and not delegates to the IOC. They may not accept from governments or from any organization or individual instructions which shall in any way bind them or interfere with the independence of their vote."

The idealistic underpinnings of the IOC are set forth in the "fundamental principles" of the Olympic movement, which comprise the opening paragraphs of the charter.

The aims of Olympism, it says, are "to promote the development of those physical and moral qualities which are the basis of sport; to educate young people through sport in a spirit of better understanding . . . and friendship, thereby helping to build a better and more peaceful world; to spread the Olympic principles throughout the world, thereby creating international goodwill; and to bring together the athletes of the world in the great four-yearly sports festival, the Olympic Games."

It is ownership of and the exclusive right to assign and distribute the familiar five-ring Olympic symbol (representing the cooperative interlocking of continents), the Olympic flag and flame, and all other attendant symbols and traditions of the Games that give the IOC its power in a modern world that is highly politicized and quite different from the one envisioned in the Olympic Charter. Quite simply the IOC has great commercial clout. It is the multinational giant of the amateur sports industry.

"The ICC governs the Olympic movement and owns the rights over the Olympic Games," states the charter, which sets out in detail the ICC's rules, by-laws and elaborate conditions for the organization, conduct and merchandising of the Games.

"Every person or organization that plays any part whatsoever in the Olympic movement shall accept the supreme authority of the IOC and shall be bound by its rules and submit to its jurisdiction," the charter stipulates.

The members of the "Olympic family" thus pledged to uphold and abide by the sovereignty of the IOC include all the most influential bodies of international amateur sport: the 26 international federations that govern the Olympic sports worldwide, and the 142 National Olympic Committees that are custodians of Olympism in their respective countries.

As in the case of the United States Olympic Committee, most of the NOCs are recognized by the governments of their countries as the umbrella authority for amateur sports within those countries.

The NOCs are recognized by the IOC and charged with the responsibility of enforcing and promoting the provisions of the charter within each country, and are also the sole authorities for representing their countries in the Olympic Games. Thus, technically, the United States does not send athletes to the Olympics; the USOC does.

Representatives of the IOC, the NOCs and the sports federations make up the so-called Tripartite Commission of the IOC, which oversees much of the grass-roots development of international sport, the interpretation of rules and training of officials, and similar matters.

But it is absolutely clear that the IOC alone -- that august group of fewer than 100 members -- maintains overall control.

According to the IOC charter, NOCs also are supposed to be independent and insulated from political pressures. Although this obviously is impossible in the modern world -- particularly in totalitarian states -- the celebrated Rule 24c of the charter states:

"NOCs must be autonomous and must resist all pressues of any kind whatsoever, whether of a political, religious or economic nature. In pursuing their objectives, NOCs may cooperate with private or government organizations. However, they must never associate themselves with any undertaking which would be in conflict with the principles of the Olympic movement and with the rules of the IOC."

Miller, in his book, points out that "Coubertin, one of the great individualists of modern times, disliked all organized government and politicians -- a sentiment which does not altogether isolate him from sportsmen of today . . . So he formed the IOC, and filled it with titled man, on the principle that the greater the standing and respect its members enjoyed the less likely politicians were to interfere with them.

". . . By 1900, when the second Olympic Games were held in Paris, Coubertin, himself a Baron, had co-opted princes from Russia and Romania, an Italian Duke, a brace of Barons from Britain and Switzerland, and countless counts from all parts of Europe."

There is only a sprinkling of titled men -- Lord Killanin, the 65-year-old Irish peer whose father was Chief Justice of Ireland, being the most notable -- on the IOC today.

There are expected to be 76 members present -- an unusually high attendance for a session preceding the Winter Games -- when Secretary of State Cyrus R. Vance delivers the speech opening the 82nd Session of the IOC on Saturday night.

But even though only a handful of them will be titled, these are strong-willed men who still do not like being dictated to by governments or politicians.

They are likely to give Vance a respectful, polite, but decidedly frosty reception. And they will probably let him know after three days of meetings -- closed, as always -- that they do not care for the resolution, passed by the USOC at President Carter's request, that this summer's Games be shifted from Moscow, delayed or called off.

If the IOC rejects the U.S. resolution, the next move will be up to the White House, which has called for Americans and citizens of like-minded nations not to participate if the Games go on as scheduled in Moscow.

A showdown between the U.S. government and its sympathizers on the one hand, and the IOC on the other, would be a fascinating battle, one bound to make Baron de Coubertin roll over in his titled grave.