how to use grid in bootstrap code example

Example 1: bootstrap grid

  

    

      One of three columns
    
    

      One of three columns
    
    

      One of three columns
    
  

Example 2: bootstrap screen sizes

The Bootstrap grid system has four classes:
xs (for phones - screens less than 768px wide)
sm (for tablets - screens equal to or greater than 768px wide)
md (for small laptops - screens equal to or greater than 992px wide)
lg (for laptops and desktops - screens equal to or greater than 1200px wide)

Example 3: bootstrap grid

This code will create 4 boxes placed side by side, which will be 
dynamically positioned, according to the size of the screen. We define 
the following behavior: 




class = "col-lg-3"   




class = "col-md-4"   




class = "col-sm-6"  




  

    

      One of four columns
    
    

      One of four columns
    
    

      One of four columns
  	
    

      One of four columns