What is the difference between data elements and domain?

Data element
A data element describes the contents of a field. For example, a data element contains the F1 help texts and the key word texts (field texts) for displaying the field on the screen. Several table fields with identical contents can refer to the same data element.

Domain
A domain describes the technical attributes of a table field. These technical attributes include the data type and the field length. Several fields with the same technical attributes can refer to the same domain. In this case, each of these fields has the technical attributes specified in this domain.