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.