Difference 1: the route is different.
In 2006, the fate/staying night was about the fate line, and saber was the heroine. Destiny/Stay Night 20 14 is about the ubw line, and Tohsaka Rin is the heroine.
Difference 2: The production companies are different.
In 2006, the production company of Fate/Stay was Studio DEEN；; The production company of Destiny/Stay Night 20 14 is ufotable.
Extended data:
Main characters:
Emiya Shirou 1
The protagonist is an orphan who was adopted by Emiya Kiritsugu, the magician black boy, ten years ago. He is one of the participants in the fifth Holy Grail War and a master of saber. Under the influence of his adoptive father, the young apprentice magician who is eager to be a "friend of justice" is born with a special liking for fencing, and his archery has reached the master level. Good at using "projection" magic.
2. Tohsaka Rin
The heroine of the UBW line, the daughter of Tohsaka Tokiomi, the heir of the magic family, Emiya Shirou's classmate, and one of the participants in the fifth Holy Grail War, is good at using the "gem" magic. As a magician, she is a master of archers. His father was killed by his disciple Kotomine Kirei in the fourth Holy Grail War, and then Kotomine Kirei became his guardian.
3, saber
Fate line heroine, one of the seven followers, the contract of the protagonist. Although petite to 154cm, but capable of worthy of the name Saber, is considered to be the best follower.