OGC well-known binary representation of geometry

The well-known binary representation for OGC geometry (WKBGeometry), provides a portable representation of a geometry value as a contiguous stream of bytes. It permits geometry values to be exchanged between a client application and an SQL database in binary form.

The well-known binary representation for geometry is obtained by serializing a geometry instance as a sequence of numeric types drawn from the set {Unsigned Integer, Double} and then serializing each numeric type as a sequence of bytes using one of two well-defined, standard binary representations for numeric types (NDR, XDR). The specific binary encoding used for a geometry byte stream is described by a one-byte tag that precedes the serialized bytes. The only difference between the two encodings of geometry is byte order. The XDR encoding is big endian, while the NDR encoding is little endian.