Toil
In plain terms
Repetitive, manual operational work that brings no lasting value.
Going deeper
Toil is the manual, automatable, repetitive grind of running systems that scales with growth and should be engineered away. SRE aims to minimize it.
Under the hood
Distinguished from valuable engineering work; reducing toil frees time for improvements.
Examples
Manual restarts, repetitive deploys, ticket toil, automatable ops tasks.
Think of it like...
Like sweeping the same floor by hand every hour instead of buying a robot vacuum.