Working Memory vs Short Term Memory: The Difference

The two terms get used interchangeably, including by people who should know better. The distinction is simple and worth having, because it explains why some mental tasks feel effortless and structurally similar ones feel exhausting.

The difference in one line

Short term memory holds. Working memory holds and does something with what it holds.

Repeating a phone number back is short term memory: storage, briefly, in the order given. Repeating it backwards is working memory: the same storage plus an operation performed on it while the storage is maintained. That added operation is what makes the second task feel so much harder despite the identical amount of information.

Why the distinction matters

Almost everything demanding in daily life sits on the working memory side.

• Following directions with three turns while watching traffic.
• Doing arithmetic in your head with a carried digit.
• Reading a long sentence where the subject arrives before a clause that delays the verb.
• Holding what you meant to say while someone finishes a different thought.
• Cooking two dishes with overlapping timings.

None of those are storage problems. They are all storage plus interference: something must be kept available while attention goes elsewhere and comes back. That is why a noisy room wrecks mental arithmetic but barely affects recognising a face.

The capacity limit, and what it really means

The famous number is seven plus or minus two, from George Miller's 1956 paper on the span of immediate memory. The figure entered popular culture and has been refined since. Later work, notably by Nelson Cowan, argues that when rehearsal and grouping are prevented, the real limit is closer to four meaningful chunks.

The important word is chunks. Consider the sequence 1, 9, 4, 5, 1, 9, 8, 9. As eight digits it is at or beyond most people's limit. As two dates, 1945 and 1989, it is two items and trivially held. The information content is identical. What changed is the packaging.

You cannot add slots. You can put more into each one.

This is why chess masters remember a real board position at a glance but do no better than novices on a random arrangement of the same pieces. Their advantage is not a bigger memory, it is a library of meaningful patterns that lets a whole position occupy a few slots.

What actually improves it

Three things reliably help, and one popular thing is doubtful.

1. Chunking. Deliberately group material into meaningful units. Phone numbers, dates, addresses, sequences of moves. This is the highest yield habit and it costs nothing.
2. Offloading. Write it down. Working memory is expensive and fragile, and a notepad has unlimited capacity. Using external memory is not cheating, it is engineering.
3. Reducing interference. Working memory is heavily disrupted by competing demands. Doing one thing at a time is not a productivity slogan, it is a direct consequence of how the system works.
4. Training programmes, where the evidence is mixed. Practising a working memory task makes you better at that task and at tasks resembling it. Whether that transfers to unrelated abilities such as general intelligence is contested, and large reviews have been sceptical. The honest position is that near transfer is well supported and far transfer is not.

That is worth saying plainly because the brain training industry has often implied otherwise. Games that involve holding and manipulating information are genuinely good practice at holding and manipulating information, which is useful in itself. Treat any promise beyond that with suspicion, including from us.

How the two show up in games

• Mostly storage. Memory Match, where you reveal cards and recall positions. The task is to hold, not to transform. See the Memory Match guide.
• Storage plus order. Simon Says, where a growing sequence must be reproduced exactly. Order is an operation, which is why span collapses faster than you expect. See the Simon Says guide.
• Storage plus rule finding. Number Sequence, where you hold the series while testing candidate rules against it. See the Number Sequence guide.
• Storage plus comparison. Balance Scale, where relationships between weights must be held and combined. See the Balance Scale guide.

If you want the deeper treatment of how memory span behaves under load, see working memory and puzzle games, and for the broader question of what brain training does and does not deliver, does brain training work.

MyRin includes these games with 600 levels each across easy, medium and hard, free on iOS and Android, designed for short daily sessions rather than long ones.

FAQ

What is the difference between working memory and short term memory?

Short term memory is passive storage: holding a few items for a short time. Working memory is storage plus manipulation: holding those items while doing something with them, such as reordering, comparing or calculating. Working memory includes short term storage but adds control.

How many things can you hold in working memory?

The old answer was seven plus or minus two, from George Miller in 1956. Later work suggests around four meaningful chunks when rehearsal is prevented. The number depends heavily on how well the material can be grouped, which is why experts appear to hold more in their own field.

Can working memory be trained?

Practice reliably improves performance on the trained task and on tasks that closely resemble it. Whether it produces broad gains in unrelated abilities is contested, and the evidence for far transfer is weak. Train it because the specific skills are useful, not because it will raise general intelligence.

What is chunking?

Grouping individual items into larger meaningful units. The digits 1,9,4,5 are four items, while 1945 as a year is one. Chunking does not raise the capacity limit, it raises how much information each slot carries, which is the practical way to hold more.