Definition

• System: A quantity of matter in space which is analyzed during a problem.
  
  
• Surroundings: Everything external to the system.
  
  
• System Boundary: A separation present between system and surrounding.

   

   Classification of the system boundary:-

   

  • Real solid boundary

  • Imaginary boundary

   

   The system boundary may be further classified as:-

   

  • Fixed boundary or Control Mass System

  • Moving boundary or Control Volume System

          The choice of boundary depends on the  problem being analyzed.

Fig 9.1   System and Surroundings

Classification of Systems