BUG

In software engineering an incorrect action or calculation is termed as an error. This can happen from a combination of a defect. A defect is referred to as a Software Bug. Usage of the term "Bug" to describe defect is an invention of hardware engineering. Bugs are also described as little faults and difficulties encountered with functioning of mechanism. So they can be attributed to software writing as bugs to indicate viruses.

Photo of what is possibly the first real bug was found in computer

"In 1946, when Hopper was released from active duty, she joined the Harvard Faculty at the Computation Laboratory where she continued her work on the Mark II and Mark III. Operators traced an error in the Mark II to a moth trapped in a relay, coining the term bug. This bug was carefully removed and taped to the log book September 9th 1945 [sic]. Stemming from the first bug, today we call errors or glitches [sic] in a program a bug."