best is an English term, which means best or excellent.
Most of the time it is used as an adjective, but it can also be used as a noun or adverb. best is the superlative of the adjective good, and the comparison is better (good, better, better which in Portuguese would be good, better, better or great).
The word best is often used after the word "the", when someone wants to qualitatively evaluate something. That was the best steak I ever had! - That was the best steak I've ever had!
best friend
The Portuguese translation of this expression in English is "best friend or friend. In this specific case, it is a way to differentiate a friend from all others, as the following sentence exemplifies: I have lots of friends, but he is my best friend. - I have a lot of friends, but he is my best friend.
Best Regards
The expression Best Regards means "greetings or best regards". It is used more in written form than spoken, more properly at the end of letters and e-mails, as a way of saying goodbye. Best Regards
expresses some formality and that is why it is common in the professional sphere, in order to demonstrate cordiality.best of
best of is an English expression that means "the best of/from/from" and is a term widely used in the music business. Usually when an artist or musical group reaches a certain level, they release a CD or DVD with their name followed by the expression best of, which means that on that disc are his best songs so far.
best seller
One best seller (in Portuguese it means "best/best sold") is a book that is identified as extremely popular for its inclusion in sales lists based on the publishing and commercial book industry and circulation statistics of the library. These lists are also published by newspapers, magazines, or bookstore chains.
In daily use, the best seller term is not generally associated with a specific level of sales, and in fact may be used loosely by the publisher for advertising purposes. best sellers they tend not to be books considered to be of superior academic value or literary quality, although there are exceptions.