| Y2K (Year 200). There was much debate around the Y2K crisis that was more commonly know as the Millennium Bug and it was thought that computers around the world would crash and never recover as the year 2000 rolled round. This never happened. |
| Yahoo was created by David Filo and Jerry Yang and is a World Wide Web directory. |
| A Yobibyte is a single unit of data storage that can be expressed as 2 to the 80th power or 1,208,925,819,614,629,174,706,176 bytes. |
| A Yottabyte is the name used for a septillion bytes, it is more commonly used to describe a measurement of information or computer storage. |
| YPN or Yahoo Publishers Network is a Yahoo run program that webmasters can enroll in to enable Yahoo pay-per-click adverts on their websites. |