The basic functionalities of 3 - Tier or N-Tier Architecture

Presentation Layer

•  Gathering information from the user
• Sending the user information to the business services from processing
• Receiving the result of the business services processing
• Presenting those results to the user

Business Layer

• Receiving input from the presentation tier.
• Interacting with the data services to perform the business operations.
• Sending the processed results to the presentation tier.

Data Service Layer

• Storage of data
• Retrieval of data
• Maintenance of data
• Integrity of data

Display Div Tags side by side

If you are using div tags and they display vertically.
   
    <div>
        Test 1
    </div>
    <div>
        Test 2
    </div>
    <div>
        Test 3
    </div>


OutPut:

Sometimes you want them to display horizontally or side by side. Then use style 'float' as shown below.
    <div style="float: left">
        Test 1
    </div>
    <div style="float: left">
        Test 2
    </div>
    <div style="float: left">
        Test 3
    </div>


OutPut: