title: does a service take up any of the app's resources?
body: <p>I have some things my app needs to do periodically
  these things - if done while running the app itself, affect its performance - in terms, they make it VERY BAD</p>
  
  <p>they have to do with downloading large jsons from the server and caching downloaded images </p>
  
  <p>if i do all those things in a service, and the app is running while the service is running as well - will it affect any of the app's performance? </p>
  
  <p>will the service take up any app memory allocated by dalvik ?</p>