What is the difference between sincerely and warm wishes in an email or Best wishes?

What is the difference between sincerely and warm wishes in an email or Best wishes?
"Sincerely" is the most neutral close that is used in correspondence. "Sincerely yours" would be used for a more formal complimentary close. (Please note; "Whenever the letter writer adds the word "yours" to their complimentary close, it tends to make the close more formal. You would use this more formal form if your letter were addressed to a dignitary or high-ranking official.) "Warm wishes" or "Best wishes" are both comparable to "Regards and Best Regards" and are considered to be an informal type of close. It would be appropriate to use an informal close if you are on a first-name basis and have a friendly, personal relationship and/or a long-term business/working relationship.Hope this helps! :)