Breaking down the key elements of a good name is difficult. It seems to be more of an art than a science. The boundary between quite a good name and a very good name is fuzzy and liable to subjective opinions.

Consider a function that is responsible for applying multiple CSS styles to a button. Imagine a scenario in which this is a standalone function. Which of the following names would you consider to be the most suitable?

• styleButton
• setStyleOfButton
• setButtonCSS
• stylizeButton
• setButtonStyles
• applyButtonCSS

You've likely picked your favorite. And there is, among those of you reading this book, bound to be disagreements. Many of these disagreements will be founded in our own biases. And many of our biases will have been conditioned by factors such as what language we speak, what programming languages we've been previously exposed to, and what types of programs we spend our time creating. There are many variances that exist between all of us and yet, somehow, we have to come up with a non-fuzzy concept for what a good or clean name is. At the very least, we can say that a good name might have the following characteristics:

• Purpose: What something is for and how it behaves
• Concept: Its core idea and how to think about it
• Contract: Expectations about how it works

This doesn't completely cover the complexity of naming, but with these three characteristics, we have a starting point. In the remainder of this section, we will learn how each of these characteristics is vital to the process of naming things.