Memory involves three main processes: encoding, storage, and retrieval. Encoding involves receiving input and transforming it into a code. Storage involves putting the encoded information into memory. Retrieval involves accessing stored information when needed. There are two main theories of memory formation: the information processing theory and the level of processing theory. The information processing theory views memory as operating similar to a computer, with information passing through sensory registers, short term memory, and long term memory. The level of processing theory suggests that deeper analysis and encoding of information at the semantic or meaning level leads to better memory compared to more shallow processing.