WKB stands for Well-Known Binary, a format for representing geographical and
geometrical data.

WKB uses 1-byte unsigned integers, 4-byte unsigned integers, and 8-byte
double-precision numbers.

* The first byte indicates the byte order. 00 for big endian, or 01 for little
endian.
* The next 4 bytes indicate the geometry type. Values from 1 to 7 indicate
whether the type is Point, LineString, Polygon, MultiPoint, MultiLineString,
MultiPolygon, or GeometryCollection respectively. 
* The 8-byte floats represent the co-ordinates.

Take the following example, a sequence of 21 bytes each represented by two hex
digits:

000000000140000000000000004010000000000000

* It's big endian
000000000140000000000000004010000000000000

* It's a POINT
000000000140000000000000004010000000000000

* The X co-ordinate is 2.0
000000000140000000000000004010000000000000

* The Y-co-ordinate is 4.0
000000000140000000000000004010000000000000

URL: https://mariadb.com/kb/en/well-known-binary-wkb-format/