What's the difference between using "both.. and" vs using just "and?"

Question

What's the difference between using "both... and" and "and"?

For example in this sentence, "Its restriction comes as both a culture shock and a challenge." how does the meaning of the sentence change if you take away the both and make it "Its restriction comes as a culture shock and a challenge."?

Answer 1

CoGEL § 13.35 Both … and emphasizes the ADDITIVE meaning of and. It separates the conjoins and puts them on the same footing, thereby dissociating the conjoins from the consequential or sequent relation that might otherwise be implied. Contrast:

• David loves Joan and (therefore) wants to marry her.
• David both loves Joan and wants to marry her.

Both . . . and also singles out the segregatory meaning of and rather than the combinatory use. Note the difference between:
• David and Joan got divorced. [ie 'from each other']
• Both David and Joan got divorced. ['so now they can get married']

At first sight, both … and appears to stand in the same relationship to and as either … or does to or. But in fact, both … and is not admissible where the conjoins are full finite clauses. There must be some kind of ellipsis. Hence, while we can have:

• Mary washed the dishes and Peter dried them.
we cannot have:

• *Both Mary washed the dishes and Peter dried them.

On the other hand, both can be inserted if the conjoins are predicates or predications :

• Mary both washed the dishes and dried them.
• This new machine will both accelerate the copying process and improve the quality of reproduction.
or if the conjoins are phrases:
• Both Mary and Peter washed the dishes.
• The regulations are both very precise and very detailed.

• "Its restriction comes as both a culture shock and challenge."

The meaning is the normal additive meaning, which is emphasized.

Answer 2

I'd say using "both ... and ..." stresses that both conjoined terms are strictly of equal 'weight' or 'value' in the sentence. For instance, in the example you gave:

• "Its restriction comes as a culture shock and challenge."
• "Its restriction comes as both a culture shock and challenge."

In the sentence using "both ... and ...", the reader gets the impression that 'culture shock' and 'challenge' are of equal importance- it is just as much a shock as it is a challenge and you cannot remove one from the other. While the sentence using just "... and ..." does put the conjoined terms on an similar 'level', the emphasis that the two are linked is much weaker when compared to the sentence with "both ... and ...".