[fpc-pascal] Best method for code reuse?

[Francisco Reyes]

Mattias Gaertner writes:

> Units is the right way.
> And even better: create a lazarus package for the new units.

Most of what I do is CLI, have not even installed lazarus.

Could someone doing CLI use a lazarus package?
What advantage of doing a lazarus package over just making it a unit?

Right now I am just getting back into pascal doing a simple open source 
utility so may be a little bit before I am up to speed. Was thinking 
of trying Lazarus later. Would I have any advantages on doing my CLI 
work from Lazarus?