RAM is a type of technology that allows access to files stored on the computer. Unlike HD memory, RAM does not permanently store content. It is responsible, however, for reading the contents when required. That is, in a non-sequential way, therefore, the English nomenclature of Random Access Memory (Random Access Memory).
To simplify the logic behind the function of RAM, it is possible to make an analogy with a study table, where all the necessary material to carry out the homework is gathered: such as pens, pencils, notebook, and books. The materials would be the files and the RAM, the table, where everything comes together and the work are done. Source: pc-mind.com
Thus, RAM can be understood as a temporary work space, because after the task is done, the files (study material) are removed from the memory (table) and kept in the HD (cabinet).
How it works
Just like the desktop, the larger the RAM, the greater it is working capacity. But table capacity is measured in area. The larger the table area, the more books fit and the faster the work gets done. Already the capacity of the RAM memory is measured by the bit stream supported in the operations.
That is, if you access a large amount of memory in the HD at one time, as many current programs require, you need a lot of RAM. These are, therefore, the megabytes or gigabytes that appear in the configurations.
RAM is a microprocessor-like chip made up of millions of transistors and capacitors. The capacitor is a part capable of storing electrons. When it is loaded, the system does a reading based on the famous binary code of “zeros and ones”. Each reading of this in zero or one means a bit of information. This reading is done very fast, it’s many in a few thousandths of a second. This is how RAM processes all the actions performed by the user.
Width and bus speed
Other characteristics that influence the processing power of RAM are the width and speed of the bus, which is a set of “wires” responsible for connecting the memory to the other components.
The width tells us the number of bits that can be sent to the CPU simultaneously. Speed is the number of times that group of bits can be sent every second.
The memory communicates with the CPU, exchanging data, and complete what is known as a bus cycle. It is this period which presents memory performance which, can be 100MHz and 32bit, for example. This means that such memory is capable of sending 32 bits of data to the processor 100 million times per second. However, there is an effect called latency, which delays the data transfer rate significantly when sending the first bit.
When buying a memory you should be aware of this transfer rate issue. It is useless for memory to have a high frequency and the system frequency to be lower because the system rate will limit that of RAM. So for a system that runs at 100MHz and 32bit, buy a memory with the same features.