Short term memory is known as working, primary, active memory. It lasts for a very short period. Short term could be described as a capacity of a mind to hold the active memory. Only a small amount of information for a short period could be held in it. The information that is held in short term could be recently processed or information retrieved from long term memory or even the result of recent mental processing that is related to working brain/memory.

Short-term-memory means the capacity of the brain to remember information only for a short period. Brief duration of this is about 3-20 seconds. The main mechanism of memory loss is decay. After entering sensory, certain information is transferred to short- term-memory. There are three operations within short term-memory that take place namely iconic, acoustic, and working memory.

Iconic is the ability of the brain to hold visual images.Acoustic is the ability of the brain to hold sound memories. As compared to iconic, acoustic lasts for a longer period. Working memory is the active memory. It is not necessary for one to move information from short-term-memory to longterm-memory, but put the information for immediate application. Transferring the information from STM to LTM involves consolidation or encoding of information. Longer the information is stored in short term memory, it would be more easily placed to long term memory.

Long term memory (LTM)

LTM is a system for storing the information for a long time or permanently. The brain stores and manages the information that is acquired and this information could be recollected for lifetime. The information could last for 30 seconds or for decades. Information from working memory is transferred to long-term-memory in a couple of seconds. However, long-term-memory is unlike the working memory, as there is possibility of decay.

There are basically two types of long-term-memory- episodic, and semantic memory. The episodic type stands for the memories of events and various experiences in a successive form. This memory helps us recollect everything that happened in our lives in a serial form. While semantic is the one which records facts, concepts, and skills that are acquired throughout our lives. This helps us to learn more facts and learn new concepts from our various experiences.

There are three main activities that are directly related to long term-memory namely storage, retrieval and deletion. Information is transferred to long-term-memory by practicing again and again. One can transfer any information fro short-term-memory to long-term-memory only by practice. Due to decay and interference, deletion is caused. Information is deleted when it becomes difficult for the brain to retrieve it again and again or certain things are forgotten naturally. There are two types of memory retrieval- recall and recognition. Sometimes we fail to recollect the information that we have. This is how the STM and LTM constitute the complete memory.