The simple meaning of Y2K is :

Y- for year

2- that's obvious

K- for thousand

So, Y2K means Year 2000 .

What exactly is wrong with the year 2000 ? Well, there is nothing wrong with the year . The problem lies in the programming of computers . You see, in the '50's the first mainframe computers were produced and put to use by banks and government agencies . Back then, memory space was of the utmost importance . These agencies and banks wanted to save memory in any way possible because of the tremendous amounts of money it would take to get more . One of the ways the computer nerds of the day invented to save memory was to reduce the date to two digits instead of four . This was a good idea back then, but this close to the new millenium it is not . Due to the absent mindedness of the computer programmers of the nineties, this practice of only using two digits for the year was carried on . When we reach the millenium the year on our computers, instead of changing to 2000 like on our calendars will, will switch to '00 . This is where the confusion begins . The year '00 can, and probably will, be interpreted by the computer as many number of dates . Among these dates are 0000, 1900, and 2000 and there is no way of predicting which will be the one, or if it will be the same in all computers .