[shric]

SRE - Site Reliability Engineer (a term Google came up with that's been adopted elsewhere) Google defined it approximately as what happens when you apply software engineering practices to what was traditionally an operations function.

SLO - Service Level Objective - the service level you strive for. If it's higher you have room for experimentation, etc.

SLI - Service Level Indicator - the actual metric(s) you use to measure a service level (latency, error rate, throughput, etc.)