Organisation structure refers to the formal arrangement of jobs, responsibilities, authority, communication, and relationships within a library and information centre. It determines who performs particular activities, who reports to whom, how decisions are made, and how different sections coordinate their work. A suitable organisational structure helps a library use its human and material resources efficiently and provide better services to users. Different models of organisation structure can be applied according to the size, objectives, functions, and administrative requirements of a library. The line organisation structure is one of the simplest models. Authority flows vertically from the head of the library to subordinate employees. Each employee normally receives instructions from one superior and is responsible for specific duties. In a small library, the librarian may directly supervise different sections such as acquisition, cataloguing, circulation, and reference services. This structure provides clear authority, quick decisions, and simplicity in administration. However, excessive dependence on the head may create a heavy workload and limit specialised decision-making. The functional organisation structure divides work according to specialised functions.