What is the difference between PhDs in the US and Europe (in terms of employment)? It is frequently mentioned that PhD students are employed in Europe (e.g. the Netherlands, Scandinavia, etc). I still don't understand how this affects a PhD program.

What is the difference when one enrols as a PhD student in the US or has a work contract in the Netherlands? Is there any specific difference in responsibilities, expectations, freedom, etc?

Please make a tangible comparison rather than listing various possibilities. If a student enrols in a PhD program in the US or in the Netherlands, how will their work and life be different?
Geographically, the UK is between the Netherlands and the US. In many aspects, the system is something in-between. There has been a long debate in the UK for giving the status of full employment to PhD students or not. This is a brief list of pros and cons argued by both sides of the debate.

Note that these are not my opinion, and I am simply narrating what I recall. A quick search in the UK academic websites can provide sufficient resources.

Pros


An employed PhD has better work conditions and rights.
They have better reception in the society. For instance, when it
comes to renting a house, PhD students are considered students, and
most houses are not available to student tenants.


Cons


PhD stipend is tax-free, but upon employment, the salary is taxable.
The salary is lower than £32,000 (typical for postdocs), and
international students should pay around £15,000 tuition fee.
non-EEA students cannot get Tier 4 student visa and should apply for
a work visa.


In conclusion, there is not much difference in terms of academic experience.