Out of curiosity

[Roger]

Why, when installing a new app do we need to also install the -libs and 
the -devel if the app is needed to make another app work.
Why cannot -libs be part of the installation if they are that important 
to the operation.
Why are -devel, which I'm guessing are development files for the app 
needed, does this mean the app is bar minimum and cannot be used when 
required by another app.
Sorry if I seem confused, Just trying to get a handle on the situation.

Thanks in advance
Roger