You can embed standardized bits of text in one page by calling from a "Template".

Template:Templateexample

This is useful, but not earth-shattering. However, you can have templates with variables in them. This means that the template text is all standard except for the bits you specify when you call the template.

Template:Templateexample2

And you can have templates inside templates (and templates inside templates inside templates.It's like turtles all the way down.)

Template:Templateexample3

And you can have templates with variables inside templates with variables.

Template:Templateexample4