title: What is different between uppercase and lowercase data type?
body: <p>For Example int and INT.
  About this two i just know int is the fundamental type and INT is windows data type both gain 4 bytes in memory and INT is use with window API.</p>
  
  <p>But i don't understand what is the major and proper different between both of them.</p>
  
  <p>Help me to understand this both fully?</p>