what is .htaccess?how is it useful?
It is a file that lives in the web root of your site. It can have instructions in it: - to redirect all non-www requests to www (to avoid duplicate content issues) - to stop people hotlinking to your images - to keep certain malicious bots completely out of your site - to password protect a folder - to make dynamic URLs look like folder-structure URLs (more friendly to search engines) - and many other things.