雲端運算就是將動態的虛擬化資源，透過網際網路以服務方式提供給使用者的運算模式，使用者不需知道如何管理那些支援雲端運算的資源。面對電子資源越來越受到重視，且資訊科技變化越來越迅速的今日，雲端運算提供圖書館能夠實現由實體跨向虛擬的服務模式，並且同時能夠簡化資訊技術導入的許多障礙。本文就雲端運算的意義、類型做簡單的說明，依據技術與服務的特性介紹常見的雲端服務功能，並透過案例的介紹，探討圖書館服務可應用之方向。

Cloud computing is a model for enabling virtual resources dynamically assigned and reassigned according to consumer demand over the internet. Users needn't possess the expertise to or control over the technology infrastructure of cloud computing. Facing the condition that the electronic resources are hightly valued increasingly and the information technology develops rapidly, the cloud computing boosts the achievement of the library physical service model going across virtual service model. It also can simplify those va rious obstacles of information technology. This paper describes the types, features and services of cloud computing. The common cloud computing services are introduced based on the characters of technology and service, and to explore the possible application in library services through some real cases.