Narration is simply a telling back. In the philosophy of Charlotte Mason, this telling back is to be done after ONE reading, listening, or seeing. Narration is the backbone of the student developing the habits necessary to learning and retaining what is learned.
There are so many ways to narrate — write down the narration (in a pleasing journal, a notebook, or even just notebook paper!), record the narration, type the narration into a variety of apps/programs, or tell the narration to someone else.
Narration forces the student (no matter the age!) to concentrate on what is read, listened to, or seen. To then coherently narrate, the student must put together in their mind what they have just learned. Telling back places the information into short-term memory.
Before going on with the material at a different time, a retelling should take place. This makes the connection with the information the brain has now placed in long-term memory.