When did IT come in to existence?

Answer 1

The answer to this question largely depends on how you define "IT".

Most would assume that you mean Information Technology, but even so, it is makes a big difference whether (or not) you want to limit it to the mechanical or electronic processing of information.

To give some important examples, in1889 Herman Hollerith was awarded a patent for "An Electric Tabulating System" which was later used to process the results of the 1890 US Census (see http://en.wikipedia.org/wiki/Herman_Hollerith#Electronic_tabulation_of_data for more details).

[An interesting footnote is that the 80 column punched card and its coding system (of course called the "Hollerith code") became the standard source of high speed computer/human interaction with mainframe computer systems in the 1960&70's (and beyond? I personally stopped working w/punched cards in 1983, so I don't know).]

[more trivia: In the same way that the width of the wagon axles that prevailed on the Roman Empire's road network lead to being the width of standard gauge axles used on European and American railways, the 80 columns of Hollerith's census cards also lead to being the standard width of computer screens those same computer systems.]

If you want to limit yourself to electronic, programmable, general purpose computers, I would chose the ENIAC which was completed at the University of Pennsylvania in 1946. For a great writeup on this issue, see: http://www.computerhope.com/issues/ch000984.htm