장 (jang) is an ubiquitous morpheme in Korean, it has however many different senses.

As a suffix:

 - It can mean letter (狀) as in 소개장 (letter of introduction), 추천장 (letter of recommendation), 초대장 (letter of invitation)

 - Added after a person's name or title, it can be used to show respect: 주인장 (respected master of a house), 노인장 (venerable elderly person), 춘부장 (esteemed father)

 - It is also very often used to mean "place" or "spot": 주차장 (parking lot), 시험장 (examination place), 작업장 (workplace)

 - It can mean funeral (장례) as in 국민장/국장 (national funeral), 사회장 (public funeral)

 - The leader (長) or head of an organization. 과장 : head of department, 사장 : head of society, 국장 : head of state

 - Finally it is also used to mean "notebook": 일기장 (diary notebook), 학습장 (exercise book), 필기장 (notebook)

As a prefix:

 - Long in duration, as in 장기간 or 장시일

 - Long in size, as in 장거리 or 장의자

Independantly:

 - Internal organs: 臟. Rarely used alone, it shares its chinese root with the most commonly used 장기 (臟器 internal organs), as well as 내장 (內臟 guts, viscera), 신장 (腎臟 kidney), 비장 (脾臟 spleen), 간장 (肝臟 liver), 폐장 (肺臟, lungs though using just 폐 is more common), 심장 (心臟 heart).

 - Intestines (腸). The same root is used in 결장 (結腸 colon), 소장 (小腸 small intestine), 대장 (大腸 large intestine)

 - As a count word for thin, plane, "paperlike" or "glasslike" objects 張 : 판유리 두 장 two panels of glass, 우표 두 장 two stamps, 접시 네 장 four plate, 얇게 썬 치즈 한 장 a thin slice of cheese

 - As a count words for cemetaries (뫼)

 - Chapter (章) 제1장 (first chapter)

 - Sauce (醬) It is used to mean any type of sauce such as soy sauce, beanpaste, etc... or as an abbreviation for soy sauce (간장). The same root can be found in the words for 간장 (soy sauce), 고추장 (chili sauce), 된장 (soybean paste)

 - A closet (欌) or any piece of furniture where one can put things (새 장: bird cage, 옺 장: wardrobe)

 - A unit of measure (one 장 = 3.314 yards)

 - A 장군 piece in Korean chess (장기).

 - "Checkmate" in Korean chess

 - A market (場) as in the expressions 1주 장 (weekly market), 장에 내다 (take to the market), 장을 세우다 (open a market), 장을 보다 (go to the market to buy or sell stuff), 장이 서다/장이 열다 (hold a market). You find the same root in the more common word for market 시장 (市場).

 - Inside organs of crustaceous (게딱지 속에 들어 있는 된장같이 누르스름한 물질)

 - A scene of theater play (연극에서, 막의 한 단락. 제1막 제3장: Act I, Scene 3)