
Product owner or product manager, that is the question.
Depending where you are or who you talk to there never seems to be a consensus on what these two roles do.
If we look around there is a clear definition of what the two roles do and they are very different from each other.
Looking at https://www.productplan.com/product-manager-vs-product-owner/ they provide a great side by side comparison:

As you can see, very different responsibilities. So why do organizations mix them up or merge them to make them one and the same?
There are a lot of reasons why this happens. Here are a few:
Lack of budget: Organizations could be in a budgetary issue and requires employees to play multiple roles to continue to produce products.
Lack of senior management involvement: Sometimes, senior leadership will not give any thought to the roles and not provide the direction needed to differentiate the two.
Lack of understanding: This might be the biggest culprit of having the responsibilities and roles mixed up. Lack of understanding sometimes falls under an organization that is saying it is an Agile Organization yet not fully agile.
The next biggest question is: why can’t we have the Product Manager be the Scrum Master?
As with the Product Owner and Product Manager responsibilities being different s,o are these with the Scrum Master.
https://www.huffpost.com/entry/the-scrum-master-vs-the-p_b_9598492
Brian de Haaff, Contributor
Co-founder and CEO of Aha! — the world’s #1 roadmap software
Here we can see the differentiation between the two roles. Although they both work with teams and do some functions outside of the group as well. They have two distinctive servives between them
The Product Manager provides the expectations of what is to be built and the Scrum Master works with the team to get it done. Yet they both do remove impediments to the group, yet depending on what needs to be taken care of may not fall into the wheelhouse of the other role. There needs to be that differentiation as it will impact the efficiency of the entire team’s work that is produced. Which in turn will impact the organization as a whole.