Refinancing with cash out , to get all money down back

[Maggie G.]

Hi. My name is Maggie,  I am a new to Biggerpockets. I heard few  podcasts on Biggerpockets  website  about  starting out to invest  with refinancing with cash out over  and  over again to buy one house after another house  .  Few investors recommended to  buy house  then refi with cash out all  money down and buy another house, so my question  is:  " How can you refi  with cash out to get all your money if bank will only give  80% of your equity"? How can you get all equity  out to buy another  home??, I just dont understand  how does it work,  can anybody explain the process  for  me?? 

I bought my single family home  a year ago  , I put 20%  down, how can I get that  20%  out to  buy  another  investemnet  home? Is it possible> What are  these  investors  talking  about?

I appreciate your help . Thank you. Maggie