Tell us what you are trying to do?
I have a CPT called Terms created by the encyclopedia/glossary/wiki plugin by Dennis Hoppe.
I would like to add a view to each of these posts with a list of all the regular posts and pages containing the term in question.
E.g. On the term "apple" I would like to add a list of all pages and posts containing the term "apple".
If the apple "term" is not actually a term (a taxonomy term) and is in fact a custom post, how are normal posts and pages "assigned" the apple "term" connected to it?
Presumably you can visit the apple "term" on the front-end as a post at a URL like site.com/term/apple/.
The "term" indeed is not a taxonomy term but a custom post. You can visit the post at an URL like site.com/term/apple/ as you said.
The plugin creates tooltips in each post or page where the term occurs and an alphabetical archive (glossary).
So if a post contains the word "apple", when you hover on it you get a tooltip with the explanation of the term.
What I would like to do: when you visit the custom post "apple" you get a list of all posts and pages where the term "apple" occurs. I imagine this can be done with a content template for the cpt "term" containing a view that is filtered by "all articles where the word "apple" (= the title of the custom post) is found".
I am just not sure how to do that: how to create a query that fonds all posts and pages with the term "apple" in the content.
How to set up the filter is the key part, and without knowing how the plugin connects its "term" posts to the posts the "term" is assigned to it's impossible to give you any direction on how to do that.
I assume you are going to setup post type relationship between post types "Terms" and "regular posts and pages", you can try these:
1) Setup many-to-many relationship between post types "Terms" and "regular posts and pages"
One "Terms" post can connect with multiple "regular posts and pages"
One page/post can connect with multiple "Terms" posts https://toolset.com/course-lesson/how-to-set-up-post-relationships-in-wordpress/
I managed to set up a post relationship between a cpt "Term" and "regular posts and pages".
I created a content template for "Term" post type with a view containing related posts (posts that have been connected to the "Term" post.
However I still have one question: is there a way to connect posts and pages automatically to each "Term" cpt instead of having to connect each post/page manually?
The scenario: if a post or page contains a certain term it is automatically added to the related posts section of the cpt 'Term" in question.
E.g. If a post contains the word "banana" it is automatically added to the related posts view in the cpt "Banana".
Is that possible?