What is .htaccess? & Where I have to place it?

The .htaccess file is a hidden text file that allows you to control the way visitors are able to access your site. Some common uses of the .htaccess file would be restricting access to certain files, or redirecting URLs.

 Please don't think more about file name, no file name required for this -  it's simply .htaccess 
(even i wasted more time on giving file name finally found that it's simply .htaccess)

 it's should be in root folder of you website

Ex: in SEO search engines will treat www.domainname.com &  domainname.com are different to avoid that
we use .htaccess file. More..


Multiple Sitemaps and Sitemap Index

The Sitemap has certain limitations. For example, it cannot contain more than 50 000 URLs and cannot be bigger than 10 MB. This is why if you plan to create a website with multiple subdirectories and Sitemaps, you will have to use Sitemap Index.
The Sitemap index allows you to include several Sitemap files under one file called Sitemap index. It uses almost the same syntax but instead of including your pages URLs, you will have to add the URLs to your Sitemaps.
Below, you can find a sample code of a Sitemap index.
<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc>http://www.domain.com/sitemap1.xml.gz</loc>
<lastmod>2004-10-01T18:23:17+00:00</lastmod>
</sitemap>
<sitemap>
<loc>http://www.domain.com/sitemap2.xml.gz</loc>
<lastmod>2005-01-01</lastmod>
</sitemap>
</sitemapindex>
As you can see the Sitemap index file uses the following XML tags:
  • loc
  • lastmod
  • sitemap
  • sitemapindex
The <loc> and the <lasmod> tags are basically the same as in the normal Sitemap file. The <sitemap> tag encapsulates information about an individual Sitemap. The <sitemapindex> tag provides information about all of the Sitemaps in the file.Be advised that the Sitemap files can be only files located under the same domain or subdomain and should be UTF-8 encoded as well.
It is strongly recommended that you place your Sitemap into the root directory of your web server. The location of a Sitemap file determines the set of URLs that can be included in it. A Sitemap file, for example, located under a subdirectory can include links of all pages in this subdirectory, but not ones above it.