difference between 'as well as' and 'and'

She is clever as well as beautiful - (it means she is beautiful and she is also clever - but in this situation people already know she is beautiful because the speaker used 'the clever' to tell the people that is not mentioned before)

She is clever and beautiful - (she is both clever and beautiful. here people don't know she is both clever and beautiful. they heard first time when speaker said it)

As well as has a similar meaning to not only … but also.

• She is clever as well as beautiful. (= She is not only beautiful, but also clever.)

Note that as well as introduces information which is already known to the listener/ reader; the rest of the sentence gives new information.

“as well” instead of “and”

(In my university publications, I notice that many enumerations use "as well" [1] instead of "and" [2]. Is this just to make the text look more sophisticated or is there a real semantic difference? When should I use one or the other?

[1] "The algorithm can process text as well as binary files."

[2] "The algorithm can process text and binary files.")

• The use of and can sometimes mean (specifically with regard to algorithms and the like) that both options can/must be true at the same time. If your algorithm cannot process both text files and binary files simultaneously then the use of and might not be exactly correct in all possible interpretations.
  By using as well as or in addition to the writer is more clearly stating that these are two separate options that can be achieved independently to one another.
  Perhaps an even clearer version would be:

  The algorithm is capable of processing either text or binary files.

• I believe that there should have been more focus on the in addition to alternative.  And I agree that “A as well as B” emphasizes A.  It seems to me that this would apply to situations where the audience would expect the statement to be true about B, but might be surprised to hear it about A.  For example,

  The shareholders’ meeting will be attended by men and women.
  The shareholders’ meeting will be attended by children as well as adults.

'As well as' and 'in addition to'

(My question is: what is followed by as well as? For example, can we say I can swim as well as cook well?)

• What is interesting in your example is that if you say: 'I can swim as well as cook well', you are stating that these are two things that you can do, whereas if you say: 'I can swim as well as I can cook', you are stating that you can do both these things to an equal degree of proficiency.
  When we use as well as - similar in meaning and usage to in addition to - as a subordinating conjunction, the '-ing' form in the verb which follows is required:
  • 'As well as playing tennis with Steve three times during the week, I (also) play badminton with my wife at the weekend.'
  • 'In addition to working on his Ph.D. dissertation, he (also) translates articles for The Weekly Review.'