Creating CDTs

What is the major difference between creating a table from CDT and  creating CDT from a table? On looking from the front end, both look similar. But the XSD file for both of them tell a different story. I have attached both the XSD files here. The one created from table is having columns defined while the other is not having such columns. Will this cause any issues? 

  
    
      @Table(name="tableCDT")
    
    
      
        
          @Id @GeneratedValue @Column(name="id", nullable=false, unique=true, columnDefinition="INT")
        
      
      
        
          @Column(name="name", columnDefinition="VARCHAR(255)")
        
      
      
        
          @Column(name="amount", columnDefinition="DOUBLE")
        
      
      
        
          @Column(name="isTrue", columnDefinition="BIT")
        
      
    
  

  
    
      
        
          @Id @GeneratedValue
        
      
      
        
          @Column(length=255)