There are three major ways of processing the memory, which include encoding, storage and retrieval.
Encoding the memory is when any event, person, object or stimuli are sensed to be important. For instance, you are at a party, and you meet someone and you want to remember their name. Such small chemical, visual, auditory and activity based stimuli first get converted into an electrical message that can be transferred from the neurons. This process is known as encoding.
The second stage of memory recording is storage. In this stage, the same memory is stored or kept in the brain to be used in due time.
The third stage is the retrieval stage. This is the process by which the memory that was once encoded and stored is recalled for use. For instance, when you meet the same person whom you met at the party a few days ago, you will instantly recognize his face due to your visual memory, his voice through your auditory complex and his name from your speech centre etc.
Our prefrontal cortex is not the centre of all the memory; instead what we do, what we say, what we hear and what we see are stored in different packages in different areas of our brain.
That is why people with a traumatic brain injury in a certain part of the brain lose part of their memory, but they can still relate to activities, it is also why people have different approaches to learning and studies. Some study visually by seeing and drawing out things while others are listeners and are more kinetic learners so they learn practically.