The ME drive can hold up to 10 cells, its only purpose is to store cells, you can add and remove cells by right clicking on it. It will also act like a cable and provide up to 8 channels without a controller.
Storing a large quantity of drives is great and having the option to mix and max 10 drives is even better but to be able to access these drives you will need either a terminal or a crafting Terminal as there is no interface with a ME Drive.
The crafting terminal will give you a crafting table within the terminal allowing you to craft items using the items within the network automatically. This can lead to some over crafting as shift clicking complete items will make as many of that item as you have resources.
These terminals will change colour depending on the colour cable they are connected to, these interfaces must be connected to either Smart cable, Covered Cable or glass cable, these will not work on dense cables or on machines
There is also a blast resistant drive from Extras cells that will hold cells but also be very blast resistant, some say it can survive a nuclear blast, this drive can only hold 3 cells:
Extra Cells also has a Drive Face, that will work just like interfaces but will hold 6 drives and take up less space:
The display of the drive is a bit buggy, there is only one drive in this bay but it is showing 3.