The most common and most likely answer to this crossword clue is the 10 letter word SUBDOMAINS
I've seen this crossword clue in The Times
S
U
B
D
O
M
A
I
N
S
Buddy explains!

The straight part
We know that "Web areas" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case web areas = subdomains.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SUBDOMAINS mean?
SUBDOMAINS noun- A domain or sphere that is part of a larger domain or sphere.
- A domain name that has been prefaced with additional parts separated with periods.
- An additional part prefaced to a domain name.