Diferente means 'different', and while it's a common word, its significance in this song is profound and incredibly enticing.
The entire song revolves around the singer's plea to a woman who has been hurt by past relationships. He repeatedly promises, "Te juro que soy diferente" (I swear I am different), trying to convince her to give love another chance. This word is the heart of his argument and the central theme, making it the most impactful and memorable word to draw a learner into the song's narrative.
Have you ever been so tired of dating that you just want to be left alone? That's the whole story in Jay Wheeler's song "Diferente." He's singing to a woman who is completely over relationships. She feels like "ningún hombre la sabe entender" (no man knows how to understand her) and she's "cansada" (tired) of suffering. She's decided it's better to be alone than to get her hopes up again.
But Jay Wheeler isn't taking no for an answer! He comes in trying to convince her that he's not like the others. His big line, which he repeats over and over, is "Te juro que soy diferente" (I swear to you that I'm different). He even says, "Yo también estuve en tu lugar" (I was also in your place), trying to show her he gets it. The whole song is his plea for her to just give him one chance, promising "yo no voy a fallar" (I'm not going to fail/let you down).