Bug
Bug
A flaw in a program that causes a system or app to behave in an unexpected or incorrect way.
In Simple Terms
A bug is when a mistake in the code or a flaw in the design causes an app or system to behave in ways it wasn't meant to. For example, it covers everyday glitches like a game character walking straight through a wall, or a website button that just doesn't respond when you click it.
Behind the Name
The word "bug" literally means "insect," and people used it to describe mechanical glitches long before computers existed. A famous story says a real moth got trapped inside an early computer and caused it to malfunction. The developer who found it recorded in their logbook that they'd found "an actual bug." That's often credited with popularizing the term.
Take a Closer Look!
A bug is when a mistake in the code or a flaw in the design makes a system behave in a way it was never meant to.
Since computers only do exactly what the program tells them to do, even a tiny mistake in the code can cause the screen to freeze or a calculation to come out wrong.
In simple terms, a bug is like a "typo" or a "mixed-up step" in a program's instructions.
Even the most skilled developers find it hard to write a perfectly flawless program from the start, so bugs are bound to show up somewhere during development.
That's why testing - carefully checking that everything works as expected - is such an essential step before an app or system goes live.
Leaving a bug unfixed can lead to serious trouble, like a service going down or personal information being leaked.
The work of fixing these bugs is called "debugging," and it plays a huge role in keeping a system safe and reliable.