this is a good answer, YMMV
https://askubuntu.com/questions/110988/how-do-i-install-packages-without-using-a-package-manager
right, so simple story, a deb is a tale of two parts, control and data
control tells the installer what is intended while the data is the data to be deployed. The data strusture itself is simply moved into place, while the control layer deals with dependencies and versioning and and pre or post behaviours that need to be applied.
pretty simple really.