This is the 5735th most frequent Swedish word.
harold
The word "harold" is not a Swedish word; it is a proper name.
In this sentence, 'Harold' is used as the proper noun for referring to an individual and subject of the sentence.
Harold arbetar som lärare i staden.
Harold works as a teacher in the city.
Here, 'Harold' is again used as a proper noun, indicating a person that is known to the speaker.
Jag känner Harold från universitetet.
I know Harold from the university.
The sentence uses 'Harold' as a proper noun referring to a person and expands on their personal context.