Comprehensive and Detailed Explanation From Exact Extract:
The term observability comes directly from control theory and refers to the ability to infer the internal state of a system from its external outputs. Modern SRE and observability practices adopt this definition.
Google’s Site Reliability Engineering guidance (SRE Book Addendum on Observability) states:
“Observability is a property of a system that allows operators to understand its internal state by examining its outputs such as logs, metrics, and traces.”
This aligns exactly with Option C, the formal definition.
Why the other options are incorrect:
A Monitoring is part of observability, but observability is much broader.
B Health checks are simply one signal; they do not represent observability.
D Data collection is a mechanism, not the definition of observability itself.
Thus, C is the correct and academically accurate definition.
[References:, Site Reliability Engineering Book Addendum: Observability, Google Cloud Architecture Framework: Observability Principles, , ]
