If databases are categorized based on their features, there are again basically three kinds: those which only allow visitors to read data, those which have search capabilities (a revolutionary contribution to research) and those which provide space for online discussions.
若以資料庫的功能來區分，也大致可分為三類，第一類只具閱覽功能；第二類有檢索功能，對研究、搜尋資料有革命性的貢獻；第三類有網路討論、教學功能。