The Compute Module is a Raspberry Pi in a more flexible form factor, intended for industrial application.
The compute module contains the guts of a Raspberry Pi (the BCM2835 processor and 512Mbyte of RAM) as well as a 4Gbyte eMMC Flash device (which is the equivalent of the SD card in the Pi). This is all integrated on to a small 67.6x30mm board which fits into a standard DDR2 SODIMM connector (the same type of connector as used for laptop memory). The Flash memory is connected directly to the processor on the board, but the remaining processor interfaces are available to the user via the connector pins. You get the full flexibility of the BCM2835 SoC (which means that many more GPIOs and interfaces are available as compared to the Raspberry Pi), and designing the module into a custom system should be relatively straightforward as we’ve put all the tricky bits onto the module itself.
1GB of RAM per the article on the new one, the link you posted is to the old Compute module.
> The CM3 contains a BCM2837 pro-
cessor (as used on the Raspberry Pi 3), 1Gbyte LPDDR2 RAM and 4Gbytes eMMC Flash. Finally the
CM3L product is the same as CM3 except the eMMC Flash is not fitted, and the SD/eMMC interface
pins are available for the user to connect their own SD/eMMC device.
This lets you design devices with a fairly powerful CPU, but still stay within the bounds of cheap manufacturing (2 or 4 layer boards, >0.5mm pitch, 6/6mil traces, no BGAs).
These kinds of modules are enabling lots of new appliances that were too difficult to build before. I'm saying "these kinds", because lots are appearing, for example the Samsung ARTIK line or boards produced according to the 96boards.org standards.
Let's say that you're trying to create a fancy internet radio for mass production. You want to base it on linux. Instead of producing a PCB with a CPU and tons of support circuitry (hard) you can instead include a SODIMM-connector (easy) and plug in a RPI compute module.
You can get away with a much simpler design and lower production tolerances by doing this - enabling you to use less time and use cheaper production techniques.
I was always under the assumption that all-in-one minicomputers were for prototyping and hobbyist engineering. I reformat my Pi often for all the little things I want to try.
Presumably at a large scale there would be resources available to design and manufacture a completely custom board -- its the low scale applications this unlocks that make it exciting.
The Compute Module is a Raspberry Pi in a more flexible form factor, intended for industrial application.
The compute module contains the guts of a Raspberry Pi (the BCM2835 processor and 512Mbyte of RAM) as well as a 4Gbyte eMMC Flash device (which is the equivalent of the SD card in the Pi). This is all integrated on to a small 67.6x30mm board which fits into a standard DDR2 SODIMM connector (the same type of connector as used for laptop memory). The Flash memory is connected directly to the processor on the board, but the remaining processor interfaces are available to the user via the connector pins. You get the full flexibility of the BCM2835 SoC (which means that many more GPIOs and interfaces are available as compared to the Raspberry Pi), and designing the module into a custom system should be relatively straightforward as we’ve put all the tricky bits onto the module itself.
source - https://www.raspberrypi.org/products/compute-module/