PCMCIA memory cards or PC cards are used to add memory (RAM, SRAM, Flash, etc.) and/or storage capacity (hard disks, CD-ROM, etc.) to computers. Common memory types include random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), Flash, and CompactFlash. Storage media include hard disks and CD-ROM drives. PCMCIA is an acronym for Personal Computer Memory Card International Association, the standardizing organization for the personal computer (PC) card. Today, the PCMCIA memory card or PC card is thestandard in portable computer expansion.

There are three form factors for PCMCIA memory cards: Type I, Type II, and Type III. Each type or form factor has the same length-by-width dimensions, 85.6 mm x 54 mm; however, each card type has a different thickness. Type I PCMCIA memory cards are 3.3 mm thick and commonly used in one-time programmable (OTP) applications. Type II PC cards are 5 mm thick. Type III PC cards are 10.5 mm thick. All three form factors were designed for a 16-bit interface, but the introduction of CardBay and CardBus permitted PCMCIA memory cards to enter the realm of 32-bit architectures by providing a 64-pin interface. This meant PCMCIA memory cards could now connect with bus standards such as peripheral component interconnect (PCI) and universal serial bus (USB). PC cards that are designed for smaller devices are not intended for use with portable computers.

PCMCIA memory cards or PC cards are used to add memory (RAM, SRAM, Flash, etc.) and/or storage capacity (hard disks, CD-ROM, etc.) to computers. Common memory types include random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), Flash, and CompactFlash. Storage media include hard disks and CD-ROM drives. PCMCIA is an acronym for Personal Computer Memory Card International Association, the standardizing organization for the personal computer (PC) card. Today, the PCMCIA memory card or PC card is thestandard in portable computer expansion.

There are three form factors for PCMCIA memory cards: Type I, Type II, and Type III. Each type or form factor has the same length-by-width dimensions, 85.6 mm x 54 mm; however, each card type has a different thickness. Type I PCMCIA memory cards are 3.3 mm thick and commonly used in one-time programmable (OTP) applications. Type II PC cards are 5 mm thick. Type III PC cards are 10.5 mm thick. All three form factors were designed for a 16-bit interface, but the introduction of CardBay and CardBus permitted PCMCIA memory cards to enter the realm of 32-bit architectures by providing a 64-pin interface. This meant PCMCIA memory cards could now connect with bus standards such as peripheral component interconnect (PCI) and universal serial bus (USB). PC cards that are designed for smaller devices are not intended for use with portable computers.

Unlike PCMCIA memory cards, a CompactFlash card has a relatively small form factor. CompactFlash cards are standardized by the CompactFlash Association and permit the high-speed, high-capacity storage of data. There are two form factors for Flash technology: CF + Type I and CF + Type II. Each type has the same thickness as its corresponding form factor for PCMCIA memory cards; however, the card lengths and widths are different. Typically, CompactFlash cards are used in hand-held computers, digital cameras, cell phones, and other consumer electronics.