Memory was once measured in MegaBytes, however, as technology has progressed, the much larger unit of Gigabytes is used. One Megabyte is 1,000,000 bytes for storage, whereas 1 GigaByte is 1,000 MegaBytes. File sizes are often measured in Kilobytes or Megabytes. A KiloByte is 1,000 bytes, it is made up of 8 bits. These bits or binary digits have a value of zero or one. Computers being electronic, zero and one break down to a switch being off or on.
Kilobytes, Megabytes, and Gigabytes are used as a bit is such a small unit of measure. For even larger storage or memory, TeraBytes or 1,000 gigabytes are used. The TeraBytes is most often used to describe storage capacity, typical sizes are 1 or 2 TeraBytes. Larger still are PetaBytes, which are 1,000 TeraBytes. PetaBytes are normally used for higher-end computing such as servers.
When we talk about processing units, the speed of the computer’s clock is expressed. 1 Hertz is one cycle in a second. At one time this was measured mainly in Megahertz or 1,000,000 cycles per second. Megahertz I still used in networking interfaces but processor technology has improved well beyond this.
Current processor speeds are measured in Gigahertz or 1,000,000,000 cycles per second. Processors and fiber optic networks operated at these speeds. With processor speeds being this much faster, modern computers can not only do more but also much faster than previously.