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When we talk about source code and the file which contains the code like CSS, HTML, JavaScript and we also talk about performance of a web site or application, what is the differences between these terms?

  • Optimization
  • Compression
  • Minification
  • Tidying
  • Concatenation
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  • Optimization - general term meaning any of the following:
  • Compression - fewer bytes through algorithmic means
  • Minification - fewer bytes by using shorter syntax with the same meaning
  • Tidying - removing code that doesn't do anything and removing redundant code
  • Concatenation - delivering all the data in one request rather than multiple requests
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+1 Thanks can you give a simple example of each using a simple css code? – Jitendra Vyas Oct 11 '11 at 16:48
Is Minification the same alpha conversion? (lambda calculus). Also code that doesnt do anything is also known as "dead code" – Raynos Oct 11 '11 at 16:49
@Raynos: 'DeadCode' is covered under Tidying. Minification would be replacing while(true) with for(;;) (both loop forever but the second one is 4 bytes shorter). – Loki Astari Oct 11 '11 at 17:35
@Jitendra: Compression - gzipped. Minification - code rewritten to be less characters but still work. Internal variables might be changed from "theXYCoordinate" to just "a". Tidying - can't get simpler than what Scott said. Concatenation - you might combine jquery, jquery ui, and your own JS all into one file. It's all the same code but 1 HTTP Request instead of 3. – AndyMcKenna Oct 11 '11 at 18:28
@Andy - +1 How to do these things with any website I develop. – Jitendra Vyas Oct 11 '11 at 18:40

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