A .deb is a Debian package. They're used in Cydia and contain files and commands to install things. This guide will cover the very basics of constructing and compiling .debs.
![[IMG]](http://dl.dropbox.com/u/40986476/debsHOWTO/Untitled.png)
There are 2 main parts to a .deb: a DEBIAN directory in the root folder, which is required; and then all the files that are going to be installed, in a directory tree matching the locations of where each file should go. To the right is an example of a .deb directory tree. The first "BF2" folder is the root of the .deb and the second is the Zeppelin theme with icons in it.The DEBIAN folder contains various files, each without an extension. Each of these files MUST contain a blank line at the end. Here's some descriptions of files that can be created in the DEBIAN folder: