What is a bug and what does it mean? The origin of the name has to do with insects

In computer science with the term bugs (literally “small insect”) are gods malfunctions or unwanted behaviors of a computer program. Also called “bugs” in Italian, these errors often derive from logical errors or syntactics inside the code (the algorithm) that defines the actions that the program must perform. The term became widespread among the population on the occasion of Millennium Bugbetween 31 December 1999 and 1 January 2000.

What’s a bugs in computer science

A bugs it’s a error in the source code of a software which can cause a failure or incorrect functioning of the program itself. The severity of these errors can vary greatly: some bugs are not even perceptible to the user, while others cause slowdowns or even crashes. Bugs become dangerous especially when they create security holes in a computer system, which hackers can be exploited to carry out cyber attacks.

There are three types of bugs:

  • Syntax errors: they are due to an imperfect use of the code language, therefore comparable to spelling errors. These errors prevent the code from being translated into machine language. They are relatively simple to detect and resolve.
  • Logical errors: they arise from problems in the structure of the code, and are therefore comparable to semantic errors. The result is that the program does not act according to the wishes of whoever wrote it and therefore does not generate the required output. They are not easy to spot and can also be complex to fix.
  • Runtime errors: occur during program execution and often involve incorrect use of memory.

The origin of the term bugs in computer science

The use of this term to indicate a malfunction probably has its origins in the English verb to bugs what does it mean “to annoy”. It would seem that this verb derives etymologically from the archaic term bugs with which they indicated themselves goblins And goblins than in stories they annoyed the protagonist.

The use of the term in the sense of “unwanted annoyance” therefore established itself long before information technology. In fact, we also find a reference in a letter that Thomas Edison sent in 1878 to William Ortonthen president of Western Union, where it says:

You were partly right, I found one “bed bug” (“bug” in the original) in my device, but it wasn’t in the actual phone. It belonged to the “callbellum” genre. The insect seems to find the conditions for its existence in all telephone calling devices.

The anecdote of the “first bug”: the Harvard moth

The most famous anecdote linked to this term, however, dates back to September 9, 1947 when the lieutenant Grace Hopper He and his team were looking for the cause of the problem affecting the computer they built at the Harvard Universitynamed Mark II.


Checking the various components they noticed the presence of one little moth who had entered the car and prevented correct functioning. After removing the insect, Grace and her team decided to stick it inside the registry Of maintenance of the computer reporting: «First actual case of bug being found» (“first case of bugs actually found”), playing with the double meaning of the term bugs both as a malfunction and as an insect.

For this reason this anecdote is often considered the most famous bug in the history of computing and the appearance of the term in this sector is commonly associated with this date.