Flash memory refers to a particular type of EEPROM, or Electronically Erasable Programmable Read Only Memory. It is a memory chip that maintains stored information without requiring a power source.

Flash memory differs from EEPROM in that EEPROM erases its content one byte at a time. This makes it slow to update. Flash memory can erase its data in entire blocks, making it a preferable technology for applications that require frequent updating of large amounts of data as in the case of a memory stick.

Inside the flash chip, information is stored in cells. A floating gate protects the data written in each cell. Tunneling electrons pass through a low conductive material to change the electronic charge of the gate in "a flash," clearing the cell of its contents so that it can be rewritten. This is how flash memory gets its name.

Flash memory is very useful in a variety of applications including:

• Your computer BIOS
• Memory sticks
• PCMCIA memory cards
• MP3 players
• Modems
• Video game cards
• Digital cellular phones
• Digital cameras

Flash memory used as a hard drive has many advantages over a traditional hard drive. It's nonvolatile or solid state, meaning there are no moving parts. It's also silent, much smaller than a traditional hard drive, and highly portable with a much faster access time. However, the advantages of a traditional hard drive are price and capacity. Hard drives are many times larger for a price that is many times smaller, comparatively speaking, megabyte for megabyte.

That said, the price of flash memory continues to drop as capacity continues to rise, making it a prize candidate for an ever-broadening set of applications.

Note: Flash memory is not the same thing as flash RAM (Random Access Memory). Flash RAM, like any type of RAM in your computer, requires a continual power source to maintain its contents.