This is the 8329th most frequent French word.
yann
"Yann" is a French male given name, equivalent to "John" in English.
In this sentence, 'Yann' is used as a proper noun, specifically the name of a person, which serves as the subject of the verb.
Je connais Yann, c'est un ami de longue date.
I know Yann, he's a long-time friend.
Here, 'Yann' is again a proper noun referring to an individual, acting as the subject carrying out the action described by the verb 'a décidé'.
Yann a décidé d'aller au marché ce matin.
Yann decided to go to the market this morning.
In this context, 'Yann' remains a proper noun and signifies the person whom the instruction pertains to regarding their expected action.