A definition which doesn't differentiate is a definition which provides no information. If your terminology is broad enough to encompass everything, it's also too broad to tell you anything.
Defining a function is already a mechanism of abstraction. You take a snippet of code and give it a name. Usually you generalize by adding parameters. Maybe you can even make it generic (C++ templates, Java Generics, Haskell typeclasses, etc). Removing the abstraction of a function means to inline the code. You could do that manually (copy&paste).
I wrote more on this here: http://beza1e1.tuxen.de/precise_abstractions.html
Abstracting is not everything there is to programming, but modern code consists nearly completely of abstractions.