Although XML data can be stored in normal file systems, it is commonly held in relational databases to take advantage of their "robust implementation verified by years of both theoretical and practical effort".
Mada XML podaci mogu da budu sačuvani u normalnim datotečnim sistemima, oni se često čuvaju u relacionim bazama podataka da bi se iskoristila njihova „robusna implementacija verifikovana godinama teorijskih i praktičnih napora”.