When installing a package R will look at the 'Depends' and 'Imports' in the DESCRIPTION file to see which additional packages need installing.
When attaching 'library()' the package to an R session then R will load any packages listed under 'Imports' and attach any listed under 'Depends'.
My question is regarding importing functions in the NAMESPACE file? I'm confused as to the purpose of importing functions in that file and exactly what it's doing.
Are imported functions in the NAMESPACE file attached to the R session when the main package is attached?
If the answer is yes then is this not what 'Depends' is already doing? The only difference i can see is that individual functions can be attached to the session using NAMESPACE where as 'Depends' attaches the entire package.