title: What is the practical reason of having two terms tier and layer in applications architecture?
body: <p>According to <a href="https://stackoverflow.com/questions/120438/whats-the-difference-between-layers-and-tiers">this answer</a> <strong>layers</strong> and <strong>tiers</strong> are different things.</p>
  
  <p>I see a practical reason of using the term <strong>layer</strong> i.e. it logically divides code so it becomes more maintainable. It's just helps ti</p>
  
  <p>But I don't see any practical reason of using the term <strong>tier</strong>. Following this conclusion I understand why people tend to use <strong>tier</strong> and <strong>layer</strong> interchangeably</p>
  
  <p>I still have a hope that the word <strong>tier</strong> has its own meaning not for nothing. So, could you give me any practical example it use
   in development?</p>