There's no difference at all. Some use the more westernized translation of the Chinese characters by spelling it “Wing Chun” and some use the more traditional Chinese translation of the characters “Ving Tsun”, which is actually closer the the Cantonese way of pronouncing the characters.

In answering the question, “Is Wing Chun really effective in a fight?” the evidence is clear it is indeed a practical and effective martial art, especially in close-range combat scenarios. Its emphasis on technique, adaptability, and the ability to defend against larger opponents make it an invaluable fighting system.

According to Bruce Lee: A Life by Matthew Polly, Lee felt that Wing Chun was “insufficient” in combat because it restricted him to certain techniques. He came to understood that the close-quarters approach of Wing Chun wasn't good for every situation.

Wing Chun is one of the world's youngest Kung Fu styles and the only one founded by a woman. That woman was Ng Mui (or Ng Mei), a Buddhist nun of China's famous Shaolin Temple. Ng Mui was recognised as one of the top five martial artists in China during the early 1700s.