What is the difference between RAM and CD ROM in the world of computer terminology?

Ram is   random access memory . 

CD Rom     compact disk     read only memory

RAM = Random access memory (computer data storage)

CD ROM = Pre-pressed compact disk wich contains data 

Two different things!

RAM = Random Access Memroy (Primary Memory / Online Memory ) having different types.  FMP, EDO, BEDO. SDRAM, etc.

CDROM = Compact Disk Read-Only Memory ( Used as Storage, available in3.5" (185-220MB estimated) and5.25" (650-700MB), also called as Optical Storage.  Modern type of Optical Storage are DVD and BlueRay discs.

RAM -> Random Access Memory

      It is a memory chip which is assembled on motherboard.

      When user types some thing through keyboard and want to store as a file, that data first moves   

         in to RAM and then CPU will move that data to Hard Disk to permanetly store it.

      The data which is present on RAM can be removed and new data can be written so many times

ROM -> READ ONLY MEMORY

     It can be memory chip fixed on motherboard for boot strap program

     It can be CD-ROM, written once and read so many times through CD / DVD Drive

     It can be DVD, wirtten once and read so many times through DVD Drive

RAM: Random Access Memory: you can say its the computer short memory

CD Rom: Compac  Disck Read Only Memory: its like writing with ink pen in a paper