The oral mucosa in the area of crenation is usually of normal color, but there may be erythema (redness) if exposed to a high degree of friction or pressure. Crenated tongue is usually asymptomatic and harmless.
ROM stands for read-only memory. It's used to store the start-up instructions for a computer, also known as the firmware. Most modern computers use flash-based ROM. It is part of the BIOS chip, which is located on the motherboard.
In a normal computer, ROM in the form of an EEPROM chip is where the BIOS is stored. RAM-Random Access Memory. This is where current processes that are running are stored and keep the data they need immediately available to them.