This is the 5044th most frequent Swedish word.
carlos
The word "Carlos" is not native to Swedish; it is a common Spanish male given name.
Here, 'Carlos' is used as a proper noun, specifically a name of a person.
Carlos är en mycket begåvad musiker.
Carlos is a very talented musician.
In this case, 'Carlos' is used to specifically identify the subject who performed the verb action.
Jag såg att Carlos skrattade åt skämtet.
I saw that Carlos laughed at the joke.
'Carlos' here acts as the subject that is being referred to in the question for involvement.