Many of our devices require memory cards and/or GSM-based SIM cards. 

Glossary:

TF Card - an SD card in a tiny size. This is the smallest of the SD cards. Often comes with a full sized SD card adapter; just slide your TF card into the SD card adapter, and then plug that into your card reader as though it were a full-sized SD card.  Sometimes these tiny cards come with TWO adapters - a mini and a full size, in that case, plug the micro into the mini card, then stick the mini card into the full size one.  These memory cards typically come in 2,4,8, 16, and 32GB capacities. Not all capacities are available in all sizes. 

[ There are other types of memory cards available at your local stores: Memory Stick (usually associated with Sony), XD cards (usually associated with Olympus), CompactFlash (and older type of card that is becoming more and more rare, but still used by pro photographers.) Increasingly, though, the SD standard is emerging as the most commonly used type of memory. As stated above, these come in three sizes, full size (still pretty small!) mini, and micro (the most common for cellphones and small electronics such as surveillance cameras. ]

Mini SD card- This is the middle size SD card format. It often comes with full sized SD card adapter; just slide your TF card into the SD card adapter, and then plug that into your card reader as though it were a full-sized SD card. 

SD card - the standard sized SD card. Newest ones have the SDHC designation for high capacity and high speed and are not compatible with older (more than three years old) reader. 

GSM SIM card - this is the tiny card that is in almost all cell phones that use the GSM standard. AT&T, T-mobile, Rogers, are all GSM-based carriers. Verizon uses CDMA technology and their phones do not have SIM cards. With a carrier such as AT&T the SIM card can be popped out of a phone, and placed in any other AT&T branded phone and it will work perfectly - handy when a phone breaks and you want to pop your SIM card in another phone that you have. Most phones will also store all the contacts on the SIM card, which means they will be available no matter what phone you place your SIM card into. All phones in Europe and Asia use the SIM card GSM standard. 

Cardslot - a memory slot in a device. Not all devices will support all sizes. See product details. 

MB - megabyte or a million bytes. 

GB - Gigabyte. A billion bytes, or 1000 megabytes. Stated another way: 1GB - 1000MB. The old hard plastic floppy disks from ten years ago held 1.44MB.  To get perspective: a tiny, fingertip-sized 2GB TF micro SD card can hold the equivalent of 1,388 floppies. An 8GB TF card can (incredibly) hold the equivalent of over 5500 of those same floppies. 

Consumption: some rough guidelines:

A video camera shooting at 

640 x 480 will usually consume about 40MB per minute

720 x 480 will usually consume about 50MB per minute

720P HD (1280 x 960 ) will usually consume about 60MB per minute. 

1080P HD (1920 x 1080) probably close to 80MB per minute