title: How is Docker light weight
body: <p>I was reading about docker . I have understood that the platform helps in removing dependencies between different software life cycles by combining the dependencies and the software together.</p>
  
  <p>In the website of docker it was written that it is light weight , I didn't get that point as how it can be light weight when it has all the dependencies packaged along with it?</p>
  
  <p>If I have multiple containers in my system that uses the same dependency i.e say we use the same external library in all the containers , will that dependency be installed again and again for all the containers??</p>
  
  <p>I am new to Docker and thus any help would be great to me.</p>