Can some one explain what "refinancing" is?

[Corey Bogaski]

Hey everyone, 

I am new to bigger pockets. I am looking at getting my first property (house hack) within the next couple months. For the sake of the example i am going to just use fake numbers to see if i understand how the process works.

So, if i buy a house for 100k, put 50k into it and it appraises for 200k; i can take 75% of the 200k (150k) and use it on another deal without paying it back??

I know the mortgage will change and everything for the property, I mainly just wanted to get the big picture of what a refinance is. Thank you to anyone who responds and i hope this can help other people as well!