The Domain Strength

when people think about the internet address, first impression is a name that looks like
www.domainname.com.
Domains .com also are among the oldest so automatically gain more respect and authority.
This symbol is very solid in western civilisation, so when someone forgets the name extension
they put the com at the end first.
That means if you have yourname.net or .biz still some traffic will go to yourname.com , whoever owns that domain.
Some DNS servers when you put the name without any extension return the address with .com ending,then when you type google in the browser you will be redirected to google.com for example.
Disputable is the second place, more webmasters prefer .org than .net
The .info extension is not very popular, as it costs the same as .org, and the price of registering .biz
was the highest, but not giving any advantages, thus .biz is the least popular.
In short, the list of preffered premium domain extensions is :
1 .com
2. .org
3. .net
4. .info
5. .biz