@Alka the utag.js is our primary JS library; it may contain tag code if tags are bundled into it. The utag.x.js refers to the individual tag template. The 'x' will correspond to the UID of the tag found in TiQ.
Mapped and UID (UID column displays the unique identifier for the tag. The UID determines the name of the tag configuration file served from the CDN. For example, tag with a UID of 1878 corresponds to the file utag.1878.js.)