Is getting a refinance easier than getting a mortgage?

[Jameson Hooton]

Hello!  I am new, and there's something that's been confusing me.

I've been listening to Brandon Turner's audiobook, and he mentions that after a certain number of mortgages, or after a certain debt-to-income ratio, it can be difficult to find a bank that will give you a mortgage.  So, he suggests turning to things like private money, and then later refinancing to pay them back.

So, my question is, do refinances work different from mortgages?  Do you not need to meet certain debt-to-income ratios, or is there not a limit to how many you can have?

Like, once you get your foot in the door through private or hard money, then you can get banks to work with you for a refi?  

Thanks for any insight you can share!
-Jameson