A chalice (from Latin 'calix', cup) is a goblet, intended to hold just drink. In general religious terms, it is a goblet intended for drinking some beverage from during a ceremony. In Christianity, a chalice is a wine cup used during the mass for the Communion service, said to contain the wine that changed into Jesus' blood. Chalices are often made of metal, and many times richly jewelled. They have been used since ancient times.
Grail is a special holy chalice.
Also of interest
A recent book by Dan Brown, The Da Vinci Code is an interesting book that merges fact and fiction, taking the reader through an exciting journey with the protagonists who are on a search for the Holy Grail. In the book Brown, purports many interesting interpretations of Sangreal and the chalice. Definately worth a read.
Chalice at the Catholic Encyclopedia