Monitoring
In plain terms
Continuously watching a system's health and performance.
Going deeper
Monitoring collects metrics and triggers alerts when things go wrong, so teams catch problems before users do. It answers 'is the system healthy right now?'
Under the hood
Combines metrics, alerting, and dashboards; the goal is meaningful alerts (avoiding fatigue) on symptoms users feel, not just raw resource stats.
Examples
Prometheus + Grafana, Datadog, CloudWatch, uptime checks, SLO alerts.
Think of it like...
Like a hospital's bedside monitor beeping vital signs and sounding an alarm the moment something drifts out of range.