I am new to Splunk and want to explore the Splunk Clouding. I have read the brief description of it at this link
I have seen somewhere about Splunk Storm, is it similar to Splunk cloud? I am bit in a dilemma here. Please Help.
Also provide me the link to download the software(if any) to use the Splunk cloud service.
There are two cloud options, Splunk Cloud and Splunk Storm. Splunk Cloud is the Enterprise solution with many more features, as mentioned on that page you linked to. Splunk Storm is now completely free. Here is an FAQ about Storm, now that it is free: http://docs.splunk.com/Documentation/Storm/latest/User/StormFreeFAQ
Neither service requires software other than a recommended small-footprint Splunk universal forwarder to send data from your machine into the great Splunk in the sky.
On the page you linked, you can click the link for "Data Sheet" that has a little more info (also here's the data sheet: http://www.splunk.com/web_assets/pdfs/secure/Splunk_Cloud_Data_Sheet.pdf). Overview docs are in the works, but even then (as now) you'll still need to contact email@example.com to use the product.