How do they program street names on gps devices?

Java

On a GPS there is a database ( e.g. NAME => AGE, (Adam, 13 Brian,900)) of names of places against LONGITUDINAL AND LATITUDINAL.

(NAME OF PLACE => LONGITUDINAL AND LATITUDINAL)

They then access the database and return the street places on a GPS map using a program they have made in a programming language e.g. Java, c sharp.