How to get space between two in lightning page?

[![apex](https://i.stack.imgur.com/s0l7e.png)](https://i.stack.imgur.com/s0l7e.png)

```
<div class="slds-col slds-size_6-of-12">     

            <span><lightning:input label="CustomerID" name="rpaId" value="{!v.RPABot.Customer_ID__c}" /></span>
             <br/>          
            <span><lightning:input label="Customer Name" name="customername" value="{!v.RPABot.Customer_Name__c}" /></span>
             <br/>            
      </div>      
   <div class="slds-col slds-size_6-of-12">              
       <span><lightning:input label="SSN" name="dob" value="{!v.RPABot.SSN__c}" /></span> 
       <br/>              
       <span><lightning:input label="DOB" name="dob" value="{!v.RPABot.DOB__c}" /></span>
       <br/>
 </div>

```