Robots.txt is a very important file when you are looking for better search engine traffic because bots visit your websites and collect complete information & data and keep a copy of your webpages in their servers. In order to allow access to your webpages you need to generate a Robots.txt file which allows/disallows bots access to files/directories on your directories.

Some Robots.txt Templates for easy use!

Allow All Bots :(recommended)
User-Agent: *
Allow: /

Block all robots
User-Agent: *
Disallow: /

The following example “/robots.txt” file specifies that no robots should visit any URL starting with “/cyberworld/map/” or “/tmp/”, or /foo.html:
# robots.txt for http://www.example.com/
User-agent: *
Disallow: /cyberworld/map/ # This is an infinite virtual URL space
Disallow: /tmp/ # these will soon disappear
Disallow: /foo.html

This example “/robots.txt” file specifies that no robots should visit any URL starting with “/cyberworld/map/”, except the robot called “cybermapper”:
# robots.txt for http://www.example.com/
User-agent: *
Disallow: /cyberworld/map/ # This is an infinite virtual URL space
# Cybermapper knows where to go.
User-agent: cybermapper
Disallow:

This example indicates that no robots should visit this site further:
# go away
User-agent: *
Disallow: /

Just add the above codes in a text file and save it as robots.txt and upload to your root folder of your hosting account using your ftp and its done. You have allowed/disallowed all the bots using the above file.