What type of architecture my project is?

Question

Hi,

        In some post i have seen the below things

          Tier represents different hardware box. Means the components are physically separated to different machines. 
           But in case of layer all component remains in same system.

        

        In Visual studio 2013 i developed a project. In solution project i took 3 projects one is web application project for Presentation logic and 2nd one is class library project for Business layer logic and the 3rd one is also class library for Data access layer logic. 
        Here 3 layers are seperated in a solution project in the same system. So i confused weather is a 3-tier architecture or a 3-layer architecture. 
        
        Please let me know which type of architecture it was..