Defining performance
Although it might seem obvious at first glance just what performance is, it's actually a pretty vague word that carries a lot of connotations. For example, does one mean speed when using the word? Do they mean frames per second? Or are they referring to memory use?
Because the word itself can be ambiguous, let's establish some terms and definitions:
Graphical performance: The length of time taken to composite the elements in the DOM, send them to the GPU, and render them on the screen.
Computing performance: The length of time a method takes to complete its task.
Frames per second: This is related to both graphical and computing performance. This is the number of screen renders we can perform per second. Ideally, apps should target sixty frames per second.
Input performance: The length of time from an input (such as a touch) to a visual confirmation that the action was understood. This does not imply that the action is complete, just that the device recognized the input...
