Creation of a new module or change of operation of a standard module is rarely required in Bitrix Framework since the majority of tasks are solved using components and their customization.
Attention! Module customization is a modification of the system kernel with all the consequences. There is a risk that the system will become inoperable after an update or you may lose the right to refer to the technical support service.
That is why module customization is an operation that is not recommended and almost prohibited. However, there is a technical possibility to do it, and in this chapter we will study an example of a simple customization.