Last week in  Aging With Geekitude, Erica shared her favorite website for information on affordable hearing aids. This week, she’s unpacking the ABCs of computer specs so you can make a more informed computer purchase.

RAM, ROM, Bits, Bytes, Gigs, Figs, Bios, Fios… every time I try to sort out technical terms I feel like Fred and Ginger singing “Tomato, tomahto, potato, potahto, let’s call the whole thing off.” (OK, Figs isn’t a technical term, but I bet you didn’t know that.)

I want to call the whole thing off because it’s so confusing, but since I also want to get a good deal on a new computer, I need to understand what all this alphabet soup means. So,  recovering technophobe that I am, I will bravely plunge into the world of computer specifications with the help of Kenny S, my computer guru.

What Is a CPU?

The CPU is the Central Processing Unit of your computer. Made of chips, it’s the central brain of the beast, the hardware that does the computing called for by the software, or computer programs. CPUs come in different speeds and with different “cores” – both of which determine how fast your computer computes – and a variety of brands are available.

CPU speeds Processors have speeds, or clock rates, which are measured in Gigaherz (GHz) and range from 1 to 3. In the past, looking at GHz was the best way to know how fast a processor was; however now many other factors determine speed, like the number of cores.

CPU Cores CPUs had just one core in the Pleistocene era three years ago. Now the better ones have more than one processor with multiple cores in each. With more than one core, the processor can work on more than one problem at a time so if, like me, you’re surfing the web, posting on Facebook, answering emails and doing your taxes all at the same time, core 1 can be on Facebook, while core 2 is on Gmail and cores 3 and 4 can work on the spreadsheet for your taxes. All this happens seamlessly in the background while you are doing other stuff!

CPU Brands Intel and AMD are the main processor brands. Which is better? It depends on which geek you talk to. Intel processors are designated as i3, i5 and i7, which refer to the number of cores – but don’t correspond to the actual number of cores. AMD processors also come with different numbers of cores: 2, 4, 6 and 8. Kenny recommends that if you’re looking for Intel to get at least an i3 or i5; if you’re looking at AMD, go for dual core or quad core.

The real test is benchmarks, where the processors are put to the test. If you really want to know which CPU is best, this site with benchmarks will enlighten you (maybe).

What’s the difference between RAM and ROM?

RAM stands for Random Access Memory. It’s like short term memory–the part of your brain that only has to remember a phone number until you’ve dialed it. More RAM allows your computer to run more programs at the same time. This really adorable animated video explains it. Tip: Turn on the captions (look for cc at the bottom) – the narrator is talking at probably 3.0 GHz.

You should have at least 4 gigabytes (GB or Gigs) of RAM, and more is better. With some exceptions (the Macbook Air among them), you can add RAM relatively inexpensively if you start running programs that demand more. Make sure the computer you buy has available slots for upgrades.

ROM stands for Read Only Memory and isn’t included in computer specs.  Unlike RAM, which comes on a removable board, ROM is hardwired into a PC and contains the programming your computer needs to boot up and perform major tasks.   RAM disappears when you turn off the computer, ROM does not.

What About Hard Drives?

The hard drive is where all your data gets stored, including programs and files. Every time you save something, it gets stored on your hard drive. Drives used to be tiny and fill up fast, but now some are so large that it’s almost impossible to fill them up unless you’re using huge programs or store a lot of videos, music, images, or big games or programs.

The size of a hard drive is measured in megabytes (MB), gigabytes (GB) or terabytes (TB). The average hard drive these days is 500 GB. My computer’s is 300 GB, and it’s not even a quarter full. I store a lot of Word (text) files, which take up very little room. My daughter has a terabyte hard drive for her SIMS games.

Solid state drives There’s a new generation of hard disks called SSD, or solid state drives. They have no moving parts, making them much lighter, faster and less fragile than traditional hard drives, which have actual magnetic disks inside that rotate. Computers with SSDs also boot up much faster and remember where you were when you crashed. So far they’ve been pricey, but as with all computer parts, prices are coming down fast.

Bits vs Bytes

Bits The size of the CPU’s register (yet another type of memory) is measured in bits. The standard for Windows used to be 32-bit, but now it’s 64-bit; you need a 64-bit system to run more than 4 gigs of RAM. A 64-bit system can run 32-bit software but not vice versa, which can be problematic. If you really want to know more about bits, here’s a good explanation that you may or may not understand (I tried, I really did – the first part is pretty simple).

Bytes Remember megabytes, gigabytes and terabytes? Along with RAM and hard disk capacities, file sizes are also are measured in bytes (file sizes can be smaller – a Word file might only be 20 kilobytes or KB).

Roughly speaking, a kilobyte is a thousand bytes, a megabyte is 1 million bytes, a gigabyte is 1 billion bytes and a terabyte is 1 trillion bytes. If you’re at a cocktail party in Silicon Valley and want to sound super nerdy, mention brontobytes, which is something like a zillion terabytes and out of our league.

What’s an Operating System?

An operating system is the software that runs your computer and all the programs you run on it. It’s also known as the OS.

A computer comes with an OS, whether it’s a Windows OS (on a PC), a Mac OS (on an Apple computer) or a Chrome OS (on one of the new Chromebooks). Some computers have a Linux OS, but you’re unlikely to encounter one because so far, only computer nerds use it.

Computer manufacturers update  their OS regularly, and a new computer usually comes with a recent version. Microsoft, which has a really bad habit of fixing what isn’t broken and pissing everyone off, has replaced its Windows 7 OS, which everyone loved, with Windows 8, which everyone hates. Since then they’ve come out with Windows 8.1, which is somewhat better than 8.

What’s a Graphics Card or Graphic Processing Unit?

The graphics card, a.k.a GPU, processes videos and 3D content – and in fact everything you see on the screen. More powerful graphics cards will play smoother video and run more sophisticated games and other 3D applications. Although it’s called a card, sometimes its not really a separate card but is included on the motherboard of the computer.

Oh, by the way, the motherboard is a big board where everything is plugged in (CPU, RAM, Hard Disks, etc.)

Is that clear? No? Well you’re not alone. I haven’t figured it all out either, but I’ve sure learned a lot researching this. Study up, because next week, you’ll find this information useful when I discuss whether you should buy a tablet, a laptop or a desktop computer.

What’s your CPU?

See more Aging With Geekitude articles.

Erica Manfred is a journalist, essayist and humorist who writes about everything from dentistry to divorce to fantasy fiction. Friend her on Facebook.