What is an NMLS# provided by a lender

[Toks Akindele]

I was recently talking to a few lenders about doing a Cashout Refinance and I noticed that some of them had an NMLS# on the marketing material they had given me. I had always assumed that Realtors had an MLS number but I didn't know lenders also do. What is this NMLS# and where can you go to verify if this numbers are legit. I am hearing a lot of horror stories about fake lenders disappearing after they get an upfront origination fee or collect appraisal fees. So I want to check the legitimacy of any lender I do business with