It is two technologies combined: SIM (security information management) & SEM (security event management) == SIEM The SIM came from the requirement to collect e

It is two technologies combined: SIM (security information management) & SEM (security event management) == SIEM The SIM came from the requirement to collect events (operations). SEM stems from the desire to monitor / detect (security). When we (the operators & security people) realized we where both collecting sort of the same data, the plan was hedged to combine resources and build something that satisfied both our needs. Marketing realized this as a great way to pitch a story that actually made sense to everyone involved: the SIEM market exploded.