The w3-sans-serif class selects a sans-serif font, without the small finishing strokes of serif fonts.
The exact font depends on the fonts available on your device.
Compare the same text without and with the class.
Norway has a total area of 385,252 square kilometers and a population of 5,438,657 (December 2020). Norway is bordered by Sweden, Finland and Russia to the north-east, and the Skagerrak to the south, with Denmark on the other side.