cms – How do wordpress, prestashop, react/angular etc integrate with each other or are they totally separate things?

The reason for this question is because for a long time I have been trying to focus more on the development of web pages and I have had small jobs in layout, and with javascript, apart from having done courses for quite some time, the problem is that when I did those courses There was no angular / react, wordpress was not so widespread etc, so now I have a bit of cocoa because although I know and have worked a little with, for example, Angular, I do not see how they integrate or relate to each other, and in many job offers I see that they ask for all these technologies as if they were a whole, although I do not see the relationship.

I know that wordpress, from what I have worked in drupal that it is not much but at least something is, it is a content manager, basically working with blocks, I suppose that wordpress and php are usually requested to be able to create custom blocks, but from now on That’s where my question begins because I have consulted with a colleague who works with wordpress and he has told me that he never programs anything, so it leaves me a bit confused.

Also, when I look for information on how wordpress integrates with other tools, such as prestashop that almost every job offer treats it as a single entity, many courses speak of them as two completely separate things, that is, they do not generally talk about how they are integrated , then, how does prestashop intervene there?, which is supposed to be a kind of manager but for purchases.

Also with environments like react, angular etc, are they independent from wordpress? Or can you relate them? I say because react / angular are normally used for node.js which is to use a server with javascript, however wordpress like drupal mainly uses php, is it possible to use both or are they different ways of working?

I have searched many times for similar information, but I do not see something detailed that can help “old web programmers” to understand how everything has changed, I usually see some loose information for example someone explaining uses the wordpress and prestashop plugin and it does not clarify me if that is the only form of integration, and everything must go through plugins, if it is a different way to obtain only the basic tools and not have to integrate everything etc.