Nativity -  a carving, model or picture representing
the birth of Jesus

A nativity can include three figures: Joseph, Mary and baby Jesus.

A nativity can include more than three figures.  In addition to representing Joseph, Mary and Jesus, it might also have shepherd(s), angel(s), animals and wise men (also referred to as the Three Kings bearing gifts).

Nativities can even be made from banana fibers!

Nativities can be made of:
stained and blown glass from Ecuador
ceramic from Peru
banana fibers from Uganda
recycled newspapers from the Phillippines
recycled magazines from Vietnam
soap stone from India
olive wood from the Holy Land (Israel)
Tagua Nut (also called vegetable ivory) from Ecuador
Jacaranda (a flowering tree) wood from Africa
metal from Colombia, South America
and many other mediums and textiles - this is not a complete list!

Other examples