Explanation for what happened to your mortgage after financing

[Sina Bigdeli]

Question:

What happened to your mortgage / loan when you finally get the house, and how is it related to the federal funds effective rate? 
my very base level understanding is that your mortgage lender sells the loan and it changes hands over and over until it ends up as govt bonds sold to private investors. 
but it’s not sure about the details or accuracy here. 
a detailed explanation would be super useful 

[Dave Skow]

@sina 

@Sina Bigdeli- if you loan is a fixed rate - your terms   wont  change ...your  escrow amount for  taxes  and insurance may be  adjusted  by the servicer  if they change  ....if your  mortgage is an adjustable - te rate and  payment will   adjust  based on the loans  index and margin and  caps  ...the fed fund rate doesnt  affect your loan ...the  loan  or the servicing of the  loan  can  be   sold  multiple times  ...its is required that the  current  servicer and the new  servicer  send you written   notice when this happens