How to use Back link
 

Can any body tell me how to use back link for search engine optimization? any help would be appreciated. Thanks in advance.

Do White hat seo,

Must check for quality websites which has good PA, DA and page rank.
Find some website related to your websites,
Participate on Forums discussions with your website signature.
Do not use same content for multiple blogs.
Do some classifieds posting on well established websites.
Do not submit your website on directories which was developed in PHPLD.(consider as spam).
Check quality work not for quantity.

Back links, is also know as incoming links, are coming links to a website or web page. Need to check your back links whether is coming from high authority sites or not. Domain of the page is good or not.

When search engines calculate the relevance of a site to a keyword, they consider the number of QUALITY inbound links to that site. So we should not be satisfied with merely getting inbound links, it is the quality of the inbound link that matters.
A search engine considers the content of the sites to determine the QUALITY of a link. When inbound links to your site come from other sites, and those sites have content related to your site, these inbound links are considered more relevant to your site. If inbound links are found on sites with unrelated content, they are considered less relevant. The higher the relevance of inbound links, the greater their quality.

The concept of PR is long gone, as google has cease to display PR of pages to public. However, Google is still using algorithms to set PR for webpages to rank them, for its use only. But it isn't for public to see.

Although, google has stopped displaying PR to public, but still some web metrics providers are providing indices to help users prioritize web pages for their use.

For example, Majestic provides Trust flow. Domain trust flow for rating domain; URL trust for rating URLs.

Similarly, Ahrefs provides UR=URL rating; and DR= Domainn rating.
And Moz provids DA=Domain Authority.

A crawler is a program used by search engines to collect data from the internet. When a crawler visits a website, it picks over the entire website's content (i.e. the text) and stores it in a databank. It also stores all the external and internal links to the website.

Back links, is also know as incoming links, are coming links to a website or web page. Need to check your back links whether is coming from high authority sites or not. Domain of the page is good or not.