The kilometer, sometimes abbreviated as the klick or k, was a well-known distance-measurement, in use from the time of the Galactic Republic onwards. A device used for measuring distance such as kilometers was the odometer.
References to "kilometers" and "klicks" sometimes occur in character dialogue in Star Wars material, for instance when Thrawn compares them to Chissvisvias. There are several possible explanations for what the Star Wars kilometer is:
A conversion of a distance-unit of a different length into a scale more familiar for the reader.
A translation of the Basic name of a unit of approximately the same size, but not exactly the same 1,000 meter length.
The real-world measurement, somehow also being used in "a galaxy far, far away..."