Scala package objects are basically code, functions, variables, classes, objects that you want available to all of your other code/files/objects in a given package. Basically it is like a system to provide utility, helper or common code all in one place.
Instead or writing an article I’ll post links to helpful resources. No reason to waste all my time writing articles if good article exist.
A minimal coverage of Package Objects by the Scala docs.
The following link is from alvin alexander – from Scala Cook Book if you don’t own it you should buy it, this is an excellent resource. This link goes into much deeper detail than the documentation.
How to put common code in Scala package objects
Scala Tutorial – Learn How To Use Package Objects – excellent tutorial on how to use Package Objects.