Views and other data components of a module can also be modified by an extension module. In the case of Views, we will usually want to add features. The presentation structure for a View is defined in the arch field, which contains XML data. This XML data can be extended by locating the place where we want the modification, and then declaring the action to perform, such as appending some more XML elements there.
For the remaining data elements, they represent records that were written to the database, and extension modules can perform write operations on them to change some values.
