# Basic Architecture
-Nominatim provides geocoding based on OpenStreetMap data. It uses a Postgresql
+Nominatim provides geocoding based on OpenStreetMap data. It uses a PostgreSQL
database as a backend for storing the data.
There are three basic parts to Nominatim's architecture: the data import,
The __address computation__ or __indexing__ stage takes the data from `place`
and adds additional information needed for geocoding. It ranks the places by
importance, links objects that belong together and computes addresses and
-the search index. Most of this work is done in Pl/pqSQL via database triggers
+the search index. Most of this work is done in PL/pgSQL via database triggers
and can be found in the file `sql/functions.sql`.
-The __search frontend__ implements the actual API. It takes queries for
-search and reverse geocoding queries from the user, looks up the data and
+The __search frontend__ implements the actual API. It takes search
+and reverse geocoding queries from the user, looks up the data and
returns the results in the requested format. This part is written in PHP
and can be found in the `lib/` and `website/` directories.