Curious what does ROM stand for? If you spend much time with computers, you'll run into those three letters sooner or later. What ROM stands for is concrete, but how it's used varies depending on context.
What does ROM stand for?
The three letters in "ROM" stand for "read-only memory." This means that you can't write data to ROM; you can only access data from it. ROM is generally used as a long-term storage option, and as a consumer, you won't have the means to change what's on a ROM or write to it.
When is ROM used?
ROM might not sound all that useful, but people actually use it in a variety of computer applications. The term "CD ROM" stands for "Compact Disc Read-Only Memory." This means that you can read data from a CD ROM, but not write it. CD ROM is often used to refer to a drive that can read CDs, as well. Audio CDs are one form of CD ROM, but you might also get a CD ROM containing a program. DVD ROM is much the same thing: a DVD that contains data that can only be read. You cannot write to a DVD ROM.
ROM is also used in hardware applications. BIOS, your computer's basic hardware instructions, lives on your motherboard in a form of hard memory called ROM. ROM is also used on some circuit boards for electronics. Finally, you might even see ROM on your video card to control the video card hardware.
When won't you use ROM?
You don't use ROM in applications where you need to re-write the data. A CD ROM, for example, cannot be erased and used again. It only ever contains the data that comes on the CD. Erasable CDs are called CD-R or CD-RW, depending on the type of disc, and they may look similar, but they work in a different manner.
Exceptions to the rule.
While ROM generally is not capable of re-writing, not all ROM falls into this category. The ROM that contains your computer's BIOS, for example, may not be wholly read-only; it may contain a small portion that can be rewritten, or may be re-writeable under certain circumstances.
You might need to update your BIOS from time to time, for example, so manufacturers often use EEPROM, or "electrically erasable programmable read-only memory," to store BIOS. With EEPROM, you can "flash" the memory to erase the data and overwrite it with new data. In this way, you can update your BIOS. This type of ROM still isn't re-writable under normal circumstances, but it works in certain scenarios.