Understanding styles

We already customized nodes and edges using several key=value options within square brackets. Examples of keys are color, shape, width, and font.

We can define our own key=value sets. In TikZ, we commonly call such a set a style; and we give it a name. The name itself is also called a key in TikZ. The benefit for us is that such styles can contain a lot of various key=value settings and even code snippets.

Using styles is like working with macros in LaTeX. We can compare styles and macros in this way:

• If we have code that we use several times, we create a macro in LaTeX. If we have graphical properties values that we use several times, we create a named style in TikZ.
• Macros in LaTeX separate formatting from the content. Styles in TikZ separate graphical properties from the content of a drawing.
• Macros and styles save us from repeating code and help structure our documents and drawings.

Named keys have properties, such as a style, and...