  We look from a theoretical perspective at the new phase of matter,
quark-gluon plasma (QGP), the new form of nuclear matter created at high
temperature and pressure. Here I retrace the path to QGP discovery and its
exploration in terms of strangeness production and strange particle signatures.
We will see the theoretical arguments that have been advanced to create
interest in this determining signature of QGP. We explore the procedure used by
several experimental groups making strangeness production an important tool in
the search and discovery of this primordial state of matter present in the
Universe before matter in its present form was formed. We close by looking at
both the ongoing research that increases the reach of this observable to LHC
energy scale $pp$ collisions, and propose an interpretation of these unexpected
results.
