sitemap.xml is necessary for the blog (or) site?

A Sitemap is an XML file on your server with which you can easily help Google crawl and index all the pages on your site. This is obviously useful for very large sites that publish a lot of new content or update the content regularly. Your web pages will still get into the search results without an xml sitemap if Google can find them to crawl your website, if you: Make sure all your pages link to at least one other on your site Links to important pages you frequent, with (varying anchor text, the navigation and page text content if you want the best results) Remember - Google needs link to find all the pages on your site, and links spread Pagerank, which help the page rank - so it is not quite a replacement xml sitemap architecture great website.

What is a sitemap xml and do I need to seo my site to Google?

(XML Sitemap protocol) has wide adoption, including support from Google, Yahoo! and Microsoft

No. You do NOT, technically,  need  an XML Sitemap to optimize a site for Google if you have a navigation system that makes sense that Google can crawl and index easily. However - in 2015 - you must have a Content Management System that produces a best practice - and you have to submit a sitemap to Google in Google Webmaster Tools. Again - best practice. Google has said recently XML and RSS is still the method of the invention are particularly useful for them to choose the recently updated content on your site.

A Sitemap is an XML file on your server with which you can easily help Google crawl and index all the pages on your site. This is obviously useful for very large sites that publish a lot of new content or update the content regularly.

Your web pages will still get into the search results without an xml sitemap if Google can find them to crawl your website, if you:

1. Make sure all your pages link to at least one other on your site
2. Links to important pages you frequent, with (varying anchor text, the navigation and   page text content if you want the best results)

Remember - Google needs link to find all the pages on your site, and links spread Pagerank, which help the page rank - so it is not quite a replacement xml sitemap architecture great website.

Sitemaps   are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling.  In its simplest form, a Sitemap is an XML file that lists URLs for a site along with additional metadata about each URL (when it was last updated, how often it usually changes, and how important,   relative to other URLs in the  site) so that search engines can more intelligently crawl the site.

Most modern CMS automatically generates xml site maps, and   Google does not ask you to send sitemaps in webmaster  tools, and I do today.

I prefer to define me the important pages with links and the depth of content manually, but the XML sitemap is the best practice in 2015 for most sites.