Q. 1. I am getting confused with the modern terminology related to godparents. What's all these new words, "sponsor" and "witness?"
A. 1. Nowadays, the Catholic Church uses three terms to reflect what was once called the two Godparents of the person being baptised.
The word "Godparents" (Godmother and Godfather), has not changed. One of each is required for the Sacrament of Baptism. Godparents, Catholics in good standing, who have received the Sacraments of Baptism, Confirmation and Communion, may also be known as the Sponsors, one female and one male.
The word "Sponsors" is synonym to the word "Godparents." There has to two "Sponsors." One is the male (the Godfather) and the other is the female (the Godmother).
When there is only one "Sponsor" available, you can have a "Christian Witness" as the second person. If the "Sponsor" is a female, the "Christian Witness" must be a male and vice-versa. There can only be one of each gender. One of the Sponsors has to be a Catholic.
The "Christian Witness" may be a baptized non-Catholic from another christian religion that is recognized by the Catholic Church. This person is a "Christian witness," not a "sponsor."
A "Christian Witness" with a Catholic Sponsor can never be a non-baptised person. For example, the Catholic Church does not permit Jewish or Muslim godparents to participate in the Sacrament of Baptism. This does not stop them from attending the Sacrament as visitors to the event.