You can use fragments to quickly create or change common elements that are used in multiple forms. You can also use fragments to share the form creation task among various specialists.
You can use fragments to reuse content in multiple form designs. When you need to use some of the same content in multiple forms, it is faster and simpler to use a fragment than to copy or re-create the content. Using fragments also ensures that the frequently used parts of a form design have consistent content and appearance in all the referencing forms.
You can use fragments to make global changes to multiple forms only once, in one file. You can change the content, script objects, data bindings, layout, or styles in a fragment, and all XDP forms that reference the fragment will reflect the changes. To update a fragment in a PDF form, you must resave the form in LiveCycle Designer ES.
For example, a common element across many forms might be an address block that includes a drop-down list object for the country. If you need to update the values for the drop-down list object, you must open many forms to make the changes. If you include the address block in a fragment, you only need to open one fragment file to make the changes.
You can use fragments to share the creation of forms among several resources. Form developers with expertise in scripting or other advanced features of LiveCycle Designer ES can develop and share fragments that take advantage of scripting and dynamic properties. Form designers can use those fragments to lay out form designs and to ensure that all parts of a form have a consistent appearance and functionality across multiple forms designed by multiple people.
You can use the LiveCycle ES repository to limit access to a fragment and to store and share fragments.
See also 

Advantages of using fragments