Those of us who consider ourselves developers, including me, are very task-oriented. We like to be guided towards optimal results, and we find ourselves uncomfortable when there is no clear path to follow. That is why we all want to know how to do things; we like step-by-step tutorials and how-tos. However, such guidelines are based on certain theories, deep knowledge and experience.
For this reason, I will not provide you, the reader, with a structured answer to the question of how to make a website faster. Instead, I aim to provide you with the reasons and theories for why things function in certain way. I will use examples that are observable in the offline world and, using principles of psychology, research and analysis in psychophysics and neuroscience, I will try to answer some “Why?” questions.
Source: Smashing Magazine