In practice
Use the performance report for queries and the coverage and enhancement reports for technical state; they answer different questions.
Export regularly. The interface keeps sixteen months, which is not long enough to compare a year-on-year seasonal pattern twice.
Why it matters
It is the only source of query-level data straight from the engine, with no sampling or modelling in between.
It is also where Google tells you about manual actions and indexing problems, which no third-party tool can see.
Related terms