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What’s the point in having “www” in a URL?
Why do we prepend our URLs with "www", isn't http:// enough? Its clearly not necessarily because it is omissible.
However there is a particular circumstance where the use of "www" breaks the URL, when there is a subdomain.
Almost everytime I tell a non technical person to go to a url like blog.stackoverflow.com they try to go to www.blog.stackoverflow.com because they think all URLs start with "www." and get confused when it doesn't work.
Is there a technical reason for the "www" or was it just invented for semantical reasons?
Is there anything being done to address this or is it considered a non issue?
The "best practice" for internet services was to use ALIASes named after roles. So you pointed people to "www.yourdomain.xyz" for web, "ftp.yourdomain.xyz", and so on even if you only had one giant computer running the entire place.
The gain was when you got a second, giant computer you could split up the roles and no one would have to change any links or configurations.
You just live in a world where 99.99% of the domains are used strictly for websites. Pointing the core domain name to a cruddy, "probably faddish and never going to amount to anything", webserver rather than a key DNS or directory authentication machine was SHEER MADNESS once upon a time. ;-)
Nothing is being done to address it except recommend that people alias www.you.blog.xyz to you.blog.xyz so that it doesn't cause issues for people who expect it. Heck, if you are using the domain for a single service on a single machine/cloud I recommend you alias *.you.domain.xyz so that ANYTHING works, even "thisshouldntwork.you.blog.xyz".
'www' is just one kind of service, of which there may be many running on any given domain. But the domain itself can only point to one* server.
Today it's a very common service, but at the time the standard (well, practice) was minted there was no real reason to assume HTTP would be used rather than, say, Gopher.
A better solution would have been for the web browser to look for SRV records from the start, but now it's kind of too late to change.
*) Yes, you can have several A records and so on, but they better be indistinguishable from a user point of view.