A word you often hear in advertisements, or in other places in your everyday life, is loan. As the name implies, this is money that a lender, such as a bank, allows you to borrow. 
     When the bank chooses to loan you money, they wish to make a profit themselves. Therefore, the bank will charge you a fee for borrowing their money. This price is called interest.                                                                                                                                                                                                                                          
              This is what happens when you borrow money from the bank 
      -     1.  
 -          You         go         to         the         bank         and         request         a         loan,         say         for         a         house         or         a         car.         The         bank         needs         to         know         how        much        you         can         borrow.         You         have         to         show         that         you         have         enough         income         to         pay         it         back.         This         is         called         ability        to        repay.         You         have         to         present         the         bank         with         documentation,         such         as         your         paycheck         stub,         and         proof         of         expenses         and         bank         account         balances,         to         demonstrate         your         ability         to         repay         the         loan.         
 -      2.  
 -          The         bank         wants         security         for         the         loan         in         the         house/car         you         buy.         If         you         don’t         pay,         they’ll         take         possession         of         the         house/car         you’ve         bought,         and         sell         it.         In         the         case         of         a         house,         this         is         called         foreclosure.        In         the         case         of         a         car,         this         is         called         repossession.        
 -     3.  
 -          You         pay         a         sum         of         money         each         month.         This         sum         is         called         your         monthly        payment.         It         is         based         on         the         total         loan         amount,         which         includes         all         fees.         That         amount         is         then         divided         up,         usually         into         a         number         of         months         during         which         you         will         periodically         make         payments         to         repay         the         loan.         
 -      4.  
 -          The         monthly         payment         is         divided         into         two         parts:         Principal        and         interest.        The         principal         is         the         part         that         covers         paying         off         the         loan.         The         interest         is         the         price         you         pay         the         bank         for         lending         you         money,         making         it         a         pure         expense         for         you.         
 
                                                                                                                                                                                                                                                  The bank has two different kinds of interest rates:         
-          
 Nominal interest rate: 
 -        
The         interest         the         bank         demands,         which         is         what         the         bank         says         it         costs.         
 -          
 Real interest rate: 
 -        
Nominal         interest         rate         +         all         additional         fees.         This         interest         rate         tells         you         how         much         your         loan         actually         costs! 
          
                                                                                                                                                                                                                                           There are two main types of loans, serial loans and annuity loans. Most personal borrowers take out annuity loans. For both types of loans the monthly rate can calculated like this: 
                                                                                                                                                                                                                                 The way the interest and principal payment parts are calculated, and therefore what the monthly payment will be, is different between the two types of loans. In the next section, we will look at serial loans, and then after that, at the much more common annuity loans.