Digital storage units in today's consumer products

As the years go by, it seems more and more likely that the future of storage is in the cloud, but until this future comes, most digital consumer products have their own (local) storage units. These units can be mechanical (HDD, CD/DVD/Blu-ray) or solid state (eMMC, SSD, flash memory card, USB flash drive).

1. Tablets and smartphones

In small form factor gadgets storage cinsists of chips. One soldered, internal chip, and one removable, in the form of a microSD card, which is also technically one chip.

2. Laptops and AIO desktops

There are four different places in a laptop/AIO, where storage units are/can be installed:

1. in a mSATA/M.2 slot on the mainboard
2. in a standard 2.5" drive bay
3. in the optical drive bay, using a bay adapter
4. in a standard 2.5" drive bay, using a 2.5" to mSATA slot adapter

In the mSATA/M.2 slots and the 2.5" to mSATA adapter you can only install SSD units, while the simple 2.5" drive bays can house classic laptop hard drives, SSDs, SSHDs or mSATA SSDs (with the use of an adapter).

*Laptops usually have an integrated SD card reader, but it's becoming less and less practical, as most devices can transfer files to USB sticks and/or wirelessly. 

3. Desktop PCs

The latest mid range to high end mainboards have an on-board M.2 slot, which are extremely fast, but there are also standard PCI-Express card size SSDs, which install in x4 or x8 slots and offer the highest read/write speeds.

In an average desktop PC there's a lot of space, so you can add as many 2.5"/3.5" HDDs, SSDs and SSHDs as you want, assuming you have enough SATA ports available. You can also use mSATA/M.2 to PCI-Express adapter cards to add 1-8 SSDs on one card, increasing speed and/or capacity. 

4. Consoles (XBOX ONE/PS4)

These quite advanced consoles are basically computers, based on AMD APUs, so the same rules should apply as for laptops, but they also have an internal flash chip for the OS. That said, if you're trying to replace the standard HDD storage unit with a bigger/faster one or with an SSD, you may run into software compatibility issues, while the hardware should theoretically work. This was/is a serious problem in some laptops, which work with a few specific hard drive models, and reject anything else ...

In the future we can expect SSDs to win the high capacity race too, as the physical limitations of magnetic disc based storage are more and more evident. The standard NAND flash memory may be replaced by newer technologies, but they'll still be chips with no moving parts.