Deciding on whether or not a computer is powerful depends upon what functions a user will be utilizing the computer for. A computer's functionality is based upon the following things:
1. Processor Speed and type - The processor is your computer's "brain" and determines how fast the computer can perform calculations. Naturally, the larger the number, the better. The processor speed is measured in units of Hertz. Pre-98 computers used megahertz. Modern computers use gigahertz. An average computer possesses 2.4 gigahertz or more. 3.5 gigahertz is about the fastest home computer you can buy at the moment.
2. Memory - The computer's memory is what allows you to utilize more than one function at a time. The memory is temporary storage space for your computer. An application -- such as Windows Word -- will write to it when it runs and delete from it when it is closed. A typical computer uses 512mb to 2 gigabytes of memory, depending on the hardware purchased.
3. Hard Drive Space - The hard drive is an area where the computer stores information. Nowadays, it is measured in gigabytes. The larger the number of gigabytes, the better. A typical modern computer possesses between 100 and 500 gigabytes. Servers have hard drive space that is large enough to be measured in terabytes.
4. Graphics functionality - A graphics card is an add-on that a user can put into a computer to handle all graphic calculations. A graphics card has its own processor on it that performs much like the processor in the computer. When graphics are being processed, the graphics card -- or GPU -- takes over and leaves the computer's core processor to handle all other functions. This is useful, because it reduces or eliminates hangs and also allows the user to run games or graphics at a higher setting.
A typical add-on graphics card's memory is measured in megabytes or even gigabytes. The higher the megabytes, the better the card.
In addition, here's a little tip to help explain the way space is measured in a computer:
1024 bytes=1 Kilo bytes
1024 KB = 1 Mega Bytes
1024MB = 1 Giga bytes
1024 GB= 1 Tera Bytes.
1024 MHz = 1 GHz