Network monitoring tools
Canonical overview pages. Each links to relevant how-to guides and config examples.
SolarWinds commercial
SolarWinds Platform (Orion): Network Monitoring Overview
What SolarWinds Orion is, what NPM/NCM/NTA actually do, how SWQL fits in, and where it makes sense versus the alternatives.
Splunk enterpriseSplunk: Log Management & SIEM Overview
How Splunk ingests, indexes and searches machine data, what SPL is, and how Enterprise, Cloud and the free tier differ.