Define Data Entry Meaning

Robert graduated from York with a 2:1 in sociology and ended up with a job which consisted largely of data entry for his sins

Friend 1:
Would you like revenge on your boss for making you work on xmas eve?

Friend 2:
Sure...what did you have in mind?

Friend 1:
Well...go on his laptop and do a little rear data entry...really stick it to him!

Friend 2:
Is that even legal?

Friend 1:
No probably not, so don't get caught!