How to choose between 8GB and 16GB RAM for MacBook Air?

RAM is used by the processor for temporary storage of data or instructions while it's running so it can quickly get at them when it needs them. The alternative is to use the disc, which is much slower to access compared to RAM. If you're doing processor-heavy stuff like photo or video or music editing and conversion and the like then the more RAM you have the better. If you're really only going to be doing the activities you state then 8GB RAM ought to be OK. If you changed your mind and started doing, say, a bit of video editing to upload stuff to Youtube, a Mac with 8GB of RAM would still work, but it would be slow and if you started doing a lot of such editing you'd get fed up pretty quickly.

The reason that you were advised that more RAM makes your Mac last longer is that if Apple brings in new applications or features in existing apps in the future it might mean that they would run slowly on your Mac or, worst case, not run at all on your device. Again, this would only be a problem if you wanted to use them.

My advice would be to upgrade the RAM if you can afford it because it will certainly help to futureproof your Mac to some extent, but don't bankrupt yourself or put yourself in difficulties to do it because for your use the standard Mac will probably be OK.

I'd suggest getting at 16 GB of RAM and at least 512 GB of internal storage. You can't expand either after purchase.

While there are some external SSDs that are very small and lightweight (about the size of a credit card, with similar thickness to that of an iPhone), any external SSD is going to be a bit inconvenient to use with a notebook computer when you are "on the run." 256 GB might be enough for basic stuff for now … but who knows what might come up during the next 9 years if you hold onto this computer for as long as you held onto the last one?

The guy in a shop told me that I should get the upgraded version with 16gb if I wanted it to last. I want it to last.

You answered your own question, and I agree with it.

All current Macbook Air models come with at least 16GB RAM.

If you just purchased one with only 8GB RAM then it must be either "old stock" or a used Mac.

They cannot be upgraded after purchase. I would return the 8GB model as soon as it is delivered and get a refund. Then order a 16GB model.

Of that I have no doubt, but Apple Store "guys" do not work on commission. They really, really do not care what you buy, or even if you buy. They just want you to be a happy Apple customer. That's it.

Which Apple Store might that be?

In the US, Apple is not selling any 8 GB Macs any more, except possibly on their Refurbished and Clearance site, whose inventory changes all the time.

I suspect someone is trying to sell you old inventory.

John Galt wrote:

Which Apple Store might that be?

Porskrog wrote:

I’m in Norway

Something got lost in translation.