Memory cards, also popularly known as media cards and flash cards, are small, detachable devices the main purpose of which is electronic data storage. You can compare them to diskettes in this regard. Moreover, memory cards can store multiple types of data. They can store games and other applications, music; videos, pictures, documents, and a lot more.

Memory cards have various applications. They are commonly used for digital photography. They are also used as data storage modules for personal digital assistants (PDA), cell phones, portable music and video players, television, computers, printers, etc. Memory cards are very popular because they are small and portable, yet they have big storage capacities. They are also quite cost-effective because they can be used and reused.

There are different types of memory cards. Following are the main memory card variants.

Compact Flash Cards

Compact Flash cards, more popularly known as plain CF cards, are typically 36mm x 43mm and weigh around 3.3g. They come in two types, a thin one (around 3.3mm) and a thick one (around 5mm). These two types of CF cards are non-interchangeable because they require different types of card readers. Their storage capacity range from 32 Mb to 32 Gb.

Memory Cards

Smart Media Cards

Smart Media cards are typically 45mm x 37mm and weigh around 2 g. They are very thin at only 0.76 mm. They used to be popular in digital photography but they have now been superseded by other media cards. When they were first manufactured, they were styled as the successor to floppy disks. They are compatible with most devices and there are adaptors that enable their use with devices with which they're not directly compatible. However, Smart Media cards have limited storage capacities with the maximum currently at only 128 Mb.

Secure Digital (SD) and Multimedia Cards (MMC)

Secure Digital cards and Multimedia cards look the same as both are around 32mm x 24mm. SD cards, however, are typically thicker and heavier at 2.1mm and 2g, respectively. However, there are now smaller and lighter SD cards popularly known as miniSD cards. SD cards also offer better security for they come with a data write protection switch. Multimedia cards do not have this security feature.

Memory Stick

Memory Sticks are so-named because they look like sticks of chewing gum. They come in a variety of sizes and were originally launched by Sony for use with the company's portable electronic devices and mobile phones. There is a Memory Stick Standard, the slimmer Memory Stick Duo, and the more advanced Memory Stick Pro. Commercially, Memory Sticks have a capacity of around 128 MB but Memory Sticks with 8-Gb capacity are already in the works. Their maximum storage capacity is pegged at 32 Gb.

xD Picture Cards

xD Picture cards were popularized by Fujifilm and Olympus. They are mainly used in digital cameras but are also used for digital voice recorders and more recently Fuji's MP3 player. They are typically 20mm x 25mm x 1.78mm in size and weigh around 2.8g.

Additional Reading on Memory Cards

For more information on memory cards, visit Memory Cards.