What's a Spec?--1

This series of articles is about functional specifications, not technical specifications. People get these mixed up. I don't know if there's any standard terminology, but here's what I mean when I use these terms.

1. A functional specification describes how a product will work entirely from the user's perspective. It doesn't care how the thing is implemented. It talks about features. It specifies screens, menus, dialogs, and so on.
2. A technical specification describes the internal implementation of the program. It talks about data structures, relational database models, choice of programming languages and tools, algorithms, etc.

When you design a product, inside and out, the most important thing is to nail down the user experience. What are the screens, how do they work, what do they do. Later, you worry about how to get from here to there. There's no use arguing about what programming language to use before you've decided what your product is going to do. In this series, I'm only talking about functional specifications.

I've written a short sample spec which should give you an idea for what a good functional specification looks like.