A redirect is used to indicate when content has moved from one location to another. For example, you may have some content at http://www.yourdomain.com/old and decide to restructure your site. As a result of this move, your content may move to http://www.yourdomain.com/critical-keyword.
Once a redirect is implemented users who go to the old versions of your pages (perhaps via a bookmark they kept for the page) will be sent to the new versions of those pages. Without the redirect, the user would get a Page Not Found (404) error. With the redirect, the web server tells the incoming user agent (whether a browser or a spider) to instead fetch the requested content from the new URL.
Why and When to Redirect:
Redirects are also important for letting search engines know when you have moved content. After you move content, the search engines will continue to have the old URL in their index and return it in their search results until they discover the page is no longer there and discover the new page. You can help speed this process up by implementing a redirect. Here are some scenarios in which you may end up needing to implement redirects:
• You have old content that expires, so you remove it.
• You find that you have broken URLs that have links and traffic.
• You change your hosting company.
• You change your CMS.
• You want to implement a canonical redirect (redirect all pages on http://yourdomain.com to http://www.yourdomain.com).
• You change the URLs where your existing content can be found for any reason.
Not all of these scenarios require a redirect. For example, you can change hosting companies without impacting any of the URLs used to find content on your site, in which case no redirect is required. However, any scenario in which any of your URLs change is a scenario in which you need to implement redirects.
Good and Bad Redirects:
It turns out that there are many ways to perform a redirect. Not all are created equal. The basic reason for this is that there are two major types of redirects that can be implemented, tied specifically to the HTTP status code returned by the web server to the browser. These are:
“301 moved permanently”:
This status code tells the browser (or search engine crawler) that the resource has been permanently moved to another location, and there is no intent to ever bring it back.
“302 moved temporarily”:
This status code tells the browser (or search engine crawler) that the resource has been temporarily moved to another location, and that the move should not be treated as permanent.
Both forms of redirect send a human or a search engine crawler to the new location, but the search engines interpret these two HTTP status codes in very different ways. When a crawler sees a 301 HTTP status code, it assumes it should pass the historical link authority (and any other metrics) from the old page to the new one. When a search engine crawler sees a 302 HTTP status code, it assumes it should not pass the historical link authority from the old page to the new one. In addition, the 301 redirect will lead the search engine to remove the old page from the index and replace it with the new one.
Read More : SEO Services in Delhi