What is the use of www in a http(s) URL? -

what use of www in url http://www.foobar.com add information url?

recently have accessed website using https://nameofthewebsite.com , browser couldn't connect. adding www made work. please explain intricacies of in url.

in case www no different other subdomain. if attempt go https://someweirdstring.nameofthewebsite.com/ wouldn't work well.

you cannot change domain name , expect things work.

if examine dns records see each subdomain can on different server , can controlled different person.

many hosting providers give third level domain in case if don't have regular one. may use http://something.yourhosting.com/ not in way related http://yourhosting.com/ or http://www.yourhosting.com.

the debate on whether best use www in domain names or omit them creates many flamewars "in internetz". use, here objective outline of arguments:

pro-www:

• it allows differentiate between different subdomains more easily. , leads easier way load balancing without expansive setup (you can have www, www2, www3, etc; , redirect needed one).
• not talks via http or https part of www. can setup file server, after there put, delete, , other commands in http. server not talk browser.
• it makes writing dns records easier. bare domain name can pain in situations.

anti-www

• most people forget write it, , confusing people have different sites on www.example.com , example.com.
• most people use browser talk via http.
• most sites own domain name, , can afford rid of unneeded third level domain name.
• load balancing can done in other ways.

both camps agree, in today's world should strive have site accessible under both bare domain , www domain (forwarding user needed). unfortunately costs money per domain work https, many sites 1 appoach, in order save money.