Internal memory is the memory where all the data of the mobile device is stored, the operating system, applications, photos, videos, music, chats, are stored in this memory so it is important to know if the device we are going to buy has of enough storage space for our needs.
The internal memory in mobile devices is equivalent to the hard drive in computers.
Currently there are not a large number of mobile devices for sale with 256 GB of internal storage due to its high cost, but this figure will become normal and more and more brands and devices will have access to this storage figure.
Due to the demands of today's devices in terms of storage, 256 Gb is a more than reasonable amount so that our device does not become obsolete in at least 2 years.
iPhones 13 cannot record video in ProRes, the highest video quality presented to date, on devices with less than 256GB due to the space each video can occupy and possibly also the storage speed that this video codec requires.