Hi Karthik,
In addition to JerryYin reply I would like to add that you can find a short protocol description in Create a new Script window which can be useful when you choose a protocol.
Image may be NSFW.
Clik here to view.
More detailed information for each protocol is available in LoadRunner user guides
As you are new to LoadRunner you can find a lot of useful information in http://www8.hp.com/us/en/software-solutions/loadrunner-load-testing/demos-documents.html#pd1=1_16_7_11_13
It contains: Demos, Videos, Technical Videos and sample courses for HP LoadRunner 11.5 and HP VuGen 11.5 under education & training > Take a Test Drive of HP Adoption Readiness Tool (ART) for LoadRunner.
Kind regards,
