It's a very common and affectionate way to express love, care, or affection towards someone.
Here's a breakdown:
* Je: I
* te: you (informal, singular)
* fais: make, do
* des: some, some of
* gros: big
* bisous: kisses
It's a phrase used in many contexts, like:
* Between friends and family: To show love and affection.
* Romantic partners: To express love and intimacy.
* Children: To express love and care.
It's similar to saying "I love you" or "I'm thinking of you" but with a more playful and affectionate tone.