There are many cases where Webmasters do not want to allow search engine bots to visit their websites. In this case, they can block the Search Engine bots to access the website by just placing a robots files. But If you are not familiar with Robots file then WordPress provide an option where you can block the search engine bots to visit your websites. This Feature is only to block search engine bots on your website. Normal users can read your every posts easily..
To Block the Search Engines Completely for your website, Login into your blog with administrative rights. Go to setting tabs in left side bar. Click on Setting tab to expand it and then Click on Privacy Option. Now Select the second option as shown in above screenshot and save the settings.
Now Search Engine Bots will never visit your website to index or Crawl the contents. You have finally blocked them. If you have changed your mind after some time and want to allow search engine bots to visit your website, do the above process and select the first option and save it. It will now give access to search engine bots to index your website.