A computer memory is one that retains the data for the computer for a certain period of time. RAM, CD, DVD, Hard disk are all part and parcel of the computer system. These devices are used mainly for storing the data from the computer. Here again, all these items differ in the capacity and in the storage speed.

The CPU ? Central Processing Unit will be connected to the main memory of the computer. The programmes and the data that are used currently or that are run currently in the computer will be stored in this main memory. But, the present era of computers do come with the RAM-Random Access Memory and a solid state memory. These devices are annexed to the CPU with the help of the memory bus. Memory Bus is otherwise called as the address bus.

In some computers, cache memory is available along with the RAM. This cache memory will possess minute chunks that are going to be used by the CPU immediately. This is installed mainly to cut short the time of fetching and in turn increase the working speed of the CPU. Thus the function of the CPU is increased by the working of the cache memory. Commonly, RAM is considered as the very vital part of the computer memory. It is made up of the integrated semi conductor chips.

The RAM can be compared with the other types of memory. The main feature that brings out RAM from the other kinds of memory is that RAM can be located from any location of the computer with the same speed. Some types of RAM chips are very capricious. Thus these RAM chips drop all the data when the power supply is off. Some of the computers are provided with the Shadow RAM which helps in copying the present data and makes the computers work very efficiently.

Earlier, the computer cost was on the very high side and hence the end users of the computer always desired to upgrade it rather then going in for a new one. But now the scenario is completely different due to the decrease in the rate of the hardware and the interest is increased to change the computers than upgrading them with the parts.

Exchange of computers is economical only in the case of home users and not in the case of high end computer users as replacement of servers is still found to be very costly. Hence for these cases, it is better to replace the computer with the desired spare parts to update the computer.

The memory is available in the market in different configurations. For laptops and desktop computers, it ranges from 128 MB to 1 GB. This capacity will be sufficient for the regular usage. More memory is required when the computer is equipped with more programmes. In these cases, it is not advisable to buy new computers and rather the same can be upgraded with the available slots for internal expansion.