“URL with WWW and URL without WWW” -Is there any difference between them?

Question

i have noticed one things , when some website are opened in any browser then in URL bar some are like

http://www.something.com

where some are l

Answer 1

In the past, every URL required the www. prefix (i.e. www.hello.com). Nowadays we have naked domains which don't require this prefix (i.e. hello.com). We still have many domains with the www. prefix for legacy reasons.

When a company wants to buy a domain name, they can buy it either with or without the prefix, or get both (for example, buy the naked domain and set-up the same domain with the www. prefix as sub-domain) and configure both to load the same website. There are technical reasons to chosing a domain with a www. prefix (allows for certain cookie blocking polices) or a naked domain (shorter url).

Usually, one of the two will be the canonical (real) domain, while the other will only redirect to the real domain. This redirect causes a delay but it's there for a reason.

If you code this redirect the right way, search engines will understand that both are the same website. Otherwise if you skip the redirect and point both domains to your files directly, search engines will think they are separate websites which will hurt your SEO (Search Engine Optimization).