The next important component of a computer is to be found in the chips where data is stored, i.e. memory. There are many kinds of memory necessary for the operation of a computer, such as ROM (read only memory) PROM (programmable read only memory), Flash Memory, which is a type of PROM and cache Memory. The only memory you will need to make any decision about is the RAM and cache. The CPU can access data in any of the RAM cell locations in any order and it writes to the memory in any order. If you add additional RAM to a computer, you can increase its ability to process programs and applications at a faster speed. There are several types of RAM, you only need to remember one — SDRAM or whatever is the most recent incarnation (forget the others when considering server configuration).
Just remember, when dealing with memory — more is better. In discussing RAM you need to know that the size of memory is measured in bytes and each byte has its own address. For example, 1 byte is 8 bits (remember the switches in the CPU is a bit), so a kilobyte (“KB”) is 1,024 bytes, megabyte (“MB”) is 1,048,576 bytes, gigabyte (“GB) is about a billion bytes and there is even a terabyte which is about one trillion bytes.