The 3-tier architecture is three different levels between the consumer and the supplier.

The first layer is the customer and the device that they use. The second level is where the supplier and consumer communicate. The last level is where the supplier’s information is stored. For example, customers details.  

The 3-tier architecture is basically the system of getting information to and from the customer and the business. 

 I was asked this by a friend and I quite simply decided to put it on here