Je n'aime pas le garçon qui habite à côté - I don't like the boy who lives next door.
C'est un gentil garçon - He's a nice young man.
Note: French waiters were once known as garçons, and it's not uncommon in old movies to hear customers shouting Garçon ! when they need more bread or whatever. This is no longer the case: garçon is considered disrespectful, kind of like calling an adult "sonny." Nowadays, the polite way to get a French waiter's attention is either by saying Monsieur ! (or Madame, if it's a woman) or by catching his (her) eye and nodding.
Related: un jeune garçon - teenage boy; un garçon d'honneur - best man, ring bearer; un garçon manqué - tomboy
Expressions: être garçon - to be a bachelor, rester garçon - to remain a bachelor, enterrer sa vie de garçon - to have a stag / bachelor party
(click the little graphic below to hear garçon pronounced)
French restaurant vocabulary | Professions in French