I agree with that, not many people call it memory, unless it is a memory card or similar. It is however still a type of computer memory and OP is asking how to erase a file in memory, which is why I try to clear up that there is two types of memory. I edited the original post to clarify that primary memory or even more specifically RAM is what people usually call memory, and that secondary memory is often called storage.

But saying you are being pedantic but then saying something that is technically entirely incorrect is not being pedantic and simply ads to confusion.

First this is r/explainitlikeimfive, accuracy is not the highest importance but a simple to understand general (but somewhat accurate) explanation is usually enough.

Secondary, there are two types of memory in a computer, primary memory (RAM, CPU cache and ROM) and secondary memory (SSD, HDD, CD, Floppy disks, tape or any other storage media).

Those two definitions are what is generally used in computers and are a very simple way of differentiating between the two categories of memory (short term vs long term) which is what you call memory and storage, both are types of memory.

The confusion comes from that Random Acces Memory contains the word “memory” and Hard Disk Drive, Solid State Drive, Compact Disk etc. doesn’t contain the word memory even though they are all different types of long term memory storage technologies.

Here is one of many links that explains the different types of computer memory in more detail: https://www.enterprisestorageforum.com/hardware/types-of-computer-memory/

There are two types of computer memory, the first one is remembering what is being done right now, it is called RAM and is what people mean most of the time when they talk about memory. It is used for example to know what pictures to show or what numbers to count with. It is similar to how you put a book in your hand when you are reading that book. All the text and images in the book is easily and quickly accessible just by flipping a page. It contains the instructions for what the computer should do, for example “delete a file”. When you are done with information in that memory you either put it back in the “shelf” or throw it away.

The other type of memory is what you are asking about, usually a Hard Disk Drive (HDD) or a Solid State Drive (SSD). It is usually called storage since it is used to store data.

It is similar to your bookshelf or a library. In the shelf there are many books that is like files. To delete a file you could remove the book from the shelf and destroy it immediately, but that would take too long time. What the computer instead does it has a long list of what books you have, how many pages they have and where they are currently sitting in the bookshelf.

When a file is deleted you just erase that book from the list, the book is still in the shelf. Next time you get a new book to put in the shelf you look in the list, check where there is a empty spot, go to that shelf and if there is any book in the spot you want to put your book you just remove the old book and put your new book there instead. The old book is destroyed and is impossible to get back at the same time as the new book is put in the shelf.