Random access memory (RAM) Edit
Random access memory is a type of memory that can be accessed randomly, ram is most common in computers, smartphones, and tablets. The more ram you have to more applications you can have up at once because the ram holds the data until you save the work and if you don’t save your work and your computer dies the ram is able to hold the information until you start it back up again.
Read only memory (ROM) Edit
ROM cannot be erased but only can be read by a user so you will not be able to take any information or data off the ROM or they will not be able to rewrite on them so good for security reasons. Rom is good for storing the BIOS because it does not require power to keep it information on it.
EEPROM (electrically erasable programmable read only memory)
This can be erased but instead of using an electrical charge rather than UN light which makes it better for digital storage.
PROM (Programmable read only memory)
This is made the same way as rom in manufacturing but you are able to program the PROM with a special types of programing language if you do not have this language you will only be able to read the information on it just like the ROM.
EPROM (Erasable programmable read only memory)
The EPROM is the same as the PROM and you can write on it with the special language but if exposed to UV light the data is erased on the EPROM.
Chace memory is normally already in the device like the CPU and storage devices, the purpose of cache is to keep information of frequently use instruction used in software so this basically speed up the loading of the application, the cache can be deleted if to large and a large cache can actually slow down the application and there for lose its purpose.