for example, I have a set of cms, or cmf, which is accumulated through previous projects, and now new projects come and need payment functions, such as WeChat Pay and Alipay.

if you write it directly, of course, you can, but this set of code, I am prepared to use for future development, it is possible that future projects do not need to pay for the function.

well, the simplest thing is to hide the menu when it is not in use, but if so, other people can still see the functions in it when they are redeveloped, and the customer does not pay for the development, so it seems unreasonable.

another way is to delete all the relevant modules, but it"s too troublesome to involve controllers, models, validators, views, and so on.

from this, I think of plug-ins, which can be installed and uninstalled, but in some cms, I have seen modules. What is the difference between the two?

and like plug-ins in wordpress, some can be displayed in the menu, which looks no different from normal functions, but I have seen in some cms that some plug-in configurations are only configured in plug-in management and are not combined with the system menu. In short, it feels so messy, there are all kinds of it.

and the background also involves rights management. If these plug-ins exist in the form of modules, they should be in rights management, right?

or can I understand that modules are large, holistic functions, such as controllers, models, and validators, while plug-ins are just an auxiliary function, such as qq login?

then all can be installed and uninstalled with one click, and all the source code is stored in a general directory with their own corresponding directories?

the concept of this piece is still a little vague. I hope all of you can give me some advice. Thank you.