Data elements are the fundamental units in BER. Encoding consists of expressing information as data elements; decoding is the reverse process. Each data element is an ordered list of three components: identifier, length, and content. A primitive data element is characterized by a content component containing no additional data elements. In a structured data element, the content component contains one or more data elements, as shown in Figure . Each component is encoded in octets; the encoded data element is the complete sequence of the octets.
Figure: BER data element structures.