Difference between Ram and Rom

RAM (Random Access Memory)

• Type of memory that can be accessed non-sequentially 
• Used to hold the temporary data that is created and used by the program.
• The more RAM a computer has, the more processing a CPU can do without accessing the hard disk, making the computer much faster. 
• The data stored on RAM is erased once the program finishes its task, or when the power to computer is cut.
• Volatile memory type, which means that it loses its content once power is removed. 
• Faster than ROM
• RAM can be written, read and overwritten again and again.

ROM (Read Only Memory)

• Used to store the code for programs that run in the processor. 
• Non volatile
• Permanent memory chip that can be read by a machine, but not written on. 
• The data stored on ROM is still there whether the computer has power or not. 
• Only written once and thereafter can only be read. 
• The most common type of programmable ROM (PROM) chip in a computer is the BIOS.

Major Difference 

1. A ROM chip does not require a constant source of power to retain the information stored on it, whereas a RAM chip does require a constant power source to retain the information. 
2. When computer is turned on, and programs are being run, the programs information is stored in the RAM chip for better efficiency and speed. 
3. However, as soon as the computer is turned off any information stored in the RAM chip is lost. With a ROM chip, any information stored on the chip remains on it with or without power.
4. ROM chips are commonly used in gaming system cartridges, like the original Nintendo, Gameboy, Sega Genesis and a number of others.  
5. ROM chips can also be found in computers, to store the programming needed to begin the initial boot up process when turning on the computer.

Source:-

• http://www.computerhope.com/
• http://www.differencebetween.net/
• http://www.webopedia.com/