A single slow or blocked fixture, one sink, one tub, one toilet, almost always means the clog sits close to that fixture, in the trap or the branch line feeding it, and it clears without affecting anything else in the house.
When more than one drain backs up together, and it is usually whichever fixture sits lowest in the house, that points further downstream, to the main line carrying everything out to the county connection.
The tool that clears one is not always the tool that clears the other. A hand auger reaches a fixture-level clog; a main line usually needs a machine built for a longer run, or a camera first if it keeps coming back.
Describing where the slowdown shows up, and whether it happens alone or alongside another fixture acting up, helps narrow that down before anyone arrives, which is why that detail is worth mentioning on the call rather than saving it for the visit itself.