I want to know that what is the "difference" between  'non-traditional
 funding  sources  and investment banks' ??

"Investment bank
Financial intermediaries who perform a variety of services, including
aiding in the sale of securities, facilitating mergers and other
corporate reorganizations, acting as brokers to both individual and
institutional clients, and trading for their own accounts."
http://biz.yahoo.com/glossary/bfglosi.html

Here are some types of "Non-traditional funding"
Sell your assets
Borrow Against the Cash Value of Your Life Insurance 
Factor 
Outsource Your Financing 
http://www.realsmallbusiness.com/money/funding/articles/open_funding_nontrad/

That web-site also has a decent description for each of those.

Notice the Investment Bank is an actual bank.  They perform many
services, and may even help you get your non-traditional funding for a
fee.