--- layout: lesson_homepage --- This lesson shows how to use the [Software Carpentry]({{ site.swc_site }}) and [Data Carpentry]({{ site.dc_site }}) lesson template. Each lesson is made up of *episodes* that are 10-30 minutes long (including time for both teaching and exercises). The episodes of this lesson explain the tools we use to create lessons and the formatting rules those lessons must follow. > ## Why "Episodes"? > > We call the parts of lessons "episodes" because > every other term (like "topic") already has multiple meanings, > and because it encourages us to think of breaking up our lessons > into chunks that are about as long as a typical movie scene, > which is better for learning than long blocks without interruption. {: .callout} Every lesson's home page is contained in `index.md`, and opens with a few pages. After that come a block stating prerequisites and a line including `syllabus.html` (which generates a summary of the lesson's episodes). > ## Prerequisites > > Use the `.prereq` style to specify prerequisites. {: .prereq}