Antonio is a Christian merchant of Venice, he agrees to vouch for a loan to Bassanio from Shylock by putting a pound of his flesh up as collateral. On the surface Antonio represents Christian charity. He is willing give money to a friend, money that he doesn't have. I have seen a few productions that emphasize Antonio being attracted to Bassanio which places another layer upon his character. Still, Antonio can be seen a somewhat a foil for the character of Shylock. He is willing to lend money free of interest out of Christian charity, Shylock is the opposite. In the end, however, Antonio isn't as charitable to Shylock the Jew.