Random-access memory facts for kids
Random-access memory (or RAM) is a special type of computer memory. It's like a temporary workspace inside your computer. RAM stores information that your computer is actively using right now. This includes parts of programs and the data they need.
Think of RAM as your desk. When you're working on a project, you put all the papers and tools you need on your desk so you can reach them quickly. RAM does the same for your computer. It holds data that the computer needs to access very fast.
You can quickly read and write information to RAM. Most RAM comes as small computer chips. The information in RAM is usually much faster to get to than data stored on a hard drive. However, there's a catch: most RAM loses all its information when you turn off the computer.
Some special RAM, called NVRAM, can keep its data even without power. But it's more expensive and a bit slower, so it's used in smaller amounts. Modern RAM uses tiny electronic switches called transistors to store data. Long ago, computers used magnetic memory instead.
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Different Kinds of RAM
Most computers today use a type of RAM called Dynamic RAM (DRAM). Over the years, DRAM has gotten faster and better.
How DRAM Has Evolved
Before 2002, many computers used what was called Single Data Rate (SDR) RAM. Since then, newer and faster versions have been developed. These include Double Data Rate (DDR), DDR2, DDR3, and now DDR4 RAM. Each new version is designed to move data even faster. This helps your computer's main processor work quickly without waiting for information.
Why RAM Types Matter
Different kinds of RAM usually don't work together in the same computer. Most computers can only use one specific type of RAM. This is because the physical connectors on the RAM chips are shaped differently for each type. This design helps make sure you use the correct RAM for your computer model.
What is Static RAM?
Another type of RAM is called Static RAM (SRAM). SRAM also needs power to keep its data. However, it doesn't need the computer to be constantly active to refresh its memory, unlike DRAM. Some SRAM chips even have a small battery built-in. This battery makes sure the data isn't lost if the computer is turned off. Many computers use a small amount of SRAM for very fast tasks, alongside a larger amount of DRAM.
Other Ways RAM is Used
While RAM is mostly used for active programs, it can also help your computer in other clever ways.
Virtual Memory Explained
Sometimes, your computer's RAM might not have enough space for all the programs and data you're using. When this happens, the computer can use a trick called virtual memory. It combines your main RAM with a part of your computer's permanent storage (like a hard drive). This creates a much larger pool of "memory."
When RAM gets full, the computer temporarily moves some less-used data to the hard drive. This frees up space in the faster RAM. The downside is that hard drives are much slower than RAM. So, using virtual memory can sometimes make your computer feel a bit slower.
What is a RAM Disk?
A computer can also set aside a portion of its RAM to act like a super-fast storage drive. This is called a RAM disk. When you turn on your computer, certain files can be copied onto this RAM disk. Because RAM is so much faster than a regular hard drive, these files will open and run incredibly quickly.
However, remember that most RAM loses its data when the computer is turned off. So, any files on a RAM disk will disappear unless they are also saved on your permanent storage. It's like having a super-fast, temporary workspace for your most important files.
Other Kinds of Computer Memory
Besides RAM, computers have other types of memory for different jobs.
Read-Only Memory (ROM)
Information that your computer always needs, and that usually can't be changed, is stored in read-only memory (ROM). ROM keeps its contents even when the computer is turned off. A key example is the BIOS (Basic Input/Output System).
The BIOS holds the most basic instructions for your computer. It tells the computer how to start up and how to handle basic tasks like input (from your keyboard) and output (to your screen). You can think of the BIOS as the part of your computer's "brain" that knows how to wake up and get everything else working. It's a very important part of how your computer functions.
Images for kids
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An example of writable volatile random-access memory. These are Synchronous Dynamic RAM modules, commonly used in personal computers, workstations, and servers.
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An 8GB DDR3 RAM stick with a white heatsink to help keep it cool.
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These IBM tabulating machines from the mid-1930s used mechanical counters to store information. This was a very early form of memory.
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A 1-megabit (Mbit) chip, one of the last models developed by VEB Carl Zeiss Jena in 1989.
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A SO-DIMM stick of laptop RAM. These are usually about half the size of desktop RAM sticks.
See also
In Spanish: Memoria de acceso aleatorio para niños
