why always companies or any brand choose their website starting from example- www.xyz.com
why www is used and why by all companies?
The use of www is not required by any technical or policy standard and many websites do not use it. Indeed , the first ever web server was called nxoc01.cern.ch. According to Paolo Palazzi, who worked at CERN along with Tim Berners -Lee, the popular use of www as subdomain was accidental; the World Wide Web project page was intended to be published at www.cern.ch while info.cern.ch was intended to be the cern home page , however the DNS records were never switched, and the practice of prepending www to an institution's website domain name was subsequently copied.