Single Point Of Control In Software

I think it's about creating single points of control for different things in programming. We can observe this throughout the software field:

  • When we begin learning C, we are told about symbolic constants and how we can use them to change value used everywhere from one place (and also prevent "magic numbers" in the code).
  • I think functions also help in this regard. We can modify the code in one place and the changes will be reflected whenever the function is called.
  • In Web design and development, the use of external Cascading Style Sheets (CSS) aids this goal.
    An external style sheet is ideal when the style is applied to many pages. With an external style sheet, you can change the look of an entire Web site by changing one file. (link)
  • Gravatar is a service allowing users to post image on its site and then any site supports Gravatar will automatically display the user's latest chosen photo.