Types of Internal Memory

-ROM-
ROM stands for Read Only Memory. The contents of Rom can only be read but not altered or written over by the user. The programs and the basic data that are required by the computer are stored onto it by the manufacturer. It is a non-volatile form of memory. We even have different variances of ROM like PROM, EPROM etc.
-RAM-
RAM stands for random Access Memory. It is volatile memory, means its data will be erased if the power supply is turned off. It is temporary form of memory where data is stored during processing and is transferred later to the secondary memory for permanent storage. Hence for faster system larger RAM is required.
-Cache-
Cache is a small amount of very fast memory designed to speed up the transfer of data from one unit to another. The data and instructions stored here are the ones that most frequently used. Since cache memory is not very, all the required information is not always found here by the system.