Once search engines like google have crawled pages on the
internet, they can extract the content material of these pages and upload it to
their indexes. In this manner, they can determine in the event that they
experience a web page that is of sufficient first-class to be ranked properly
for applicable keywords (Google created a quick video to provide an explanation
for that procedure.)
When they’re determining this, the engines like google don’t
just take a look at the content material of the web page — they also have a
look at the number of links pointing to that web page from external websites,
and the exceptional of those outside web sites. Generally speaking, the extra
first-rate websites that link to you, the more likely you're to rank properly
in search results.
HERE IS THE LINKS