This page shows you how to get started with the functions in H3 that convert points to cell identifiers, and from cell identifiers back to geometry. These are the core indexing functions used in many applications of H3.
Point / cell
First, we'll take the coordinates of the Ferry Building in San Francisco and find the containing H3 cell:
The result is the identifier of the hexagonal cell in H3 containing this point. We can retrieve the centroid of this cell:
Note that the result of this example is not our original coordinates. That's because the identifier represents the hexagonal cell, not the coordinates. All points indexed in H3 within the bounds of this cell will have the same identifier. We can find the bounds of this cell: