Exactly. So far they were emphasizing the part about processing data and doing calculations (処理する / 計算する). In the mentioned panel on p.46 they are introducing two more concepts as both of you addressed:
- Data Compression (圧縮)
- Parity / Parity checks (パリティ)
The 「データを小さくする」briefly explains what 圧縮 is and the 「動きにまちがいがないかを調べる」what パリティ is.
As for the discussion on memory: I’m not super up to date with all the fancy new hardware stuff but in general we have a trade-off between speed and size. In the following I’ll cluster it into three groups but you can always differentiate it into more clusters, I guess.
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Cache memory - date that is hold in cache memory can be accessed very fast. The amount of data that can be hold in cache is very limited though. It usually holds data that is needed by the CPU for immediate calculations. Nowadays graphic cards probably have their own caches for GPUs as well… Feel free to dive into it if you like
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Main memory - this is where most of the action happens. You have the operating system in here and the different apps you are running and relevant data. Reading data from here is a way slower than reading from cache but it can hold multiple gigabytes already.
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Storage - this is where the data is stored. Data in here is persistent even without a connection to electricity. Hard disk drives (HDD) is what often comes in mind first. But other media can be used as well. In the manga they introduced DVD or CD-ROM. Modern storage also includes USB drive or Solid-state drives (SSD), for example. Reading from storage is very slow but the amount of data that can be stored is very big.
The term RAM refers to a type of memory with certain technical attributes. It is called ‘random-access memory’ and as the term implies, data hold in RAM can be randomly read from or written into the memory. A different type of memory would be ROM which is a ‘read-only memory’.
RAM technology is what is used to realize main memory and if I interpreted the linked Wikipedia article correctly DDR4 is still a modern player here. But again, I’m not a hardware person
Maybe it depends on the perspective you’d like to highlight For example I’d use the term main memory when talking about something from a function oriented perspective. Example “Apps are run in main memory and data is then stored on disk.” I’d use the term RAM if I want to highlight the technical aspects. I wouldn’t call it a RAM disk as technically it is not a disk…
Very valid point I’d sometimes only say " I need more memory." or “Not enough memory” as this would be my default assumption for memory in a colloquial discussion.
I’m not sure about all the different possible terms but to be on the safe side you can simply go with storage, I guess. HDD is very common and it can be internal or external. But other types of storage exist, as mentioned above.