What is debugging?

When you write an algorithm or code, it often does something you didn't expect. The mistake is called a bug, and fixing it is debugging. Every programmer, from beginners to experts, spends a lot of time debugging. A bug doesn't mean you're bad at coding; it means you're coding.

Bugs come in a few types:

• Syntax errors: the code is written wrongly, like a missing bracket or a misspelt command. The computer can't run it.
• Logic errors: the code runs, but does the wrong thing, such as turning left instead of right or repeating 3 times instead of 4.
• Missing steps: a step was left out of the algorithm.

Good debuggers work like detectives. They predict what should happen, run the program, compare the result with their prediction, and narrow down where it goes wrong. Changing one thing at a time makes it easier to see what fixed the problem.

The word "bug" was used for faults in machines long before computers; inventors used it in the 1800s. A famous story comes from 1947, when engineers working on the Harvard Mark II computer, a team that included Grace Hopper, found a real moth stuck inside. They taped it into their logbook as the "first actual case of bug being found". The joke worked because everyone already called faults bugs.

Debugging takes patience. It is a great example of a growth mindset: every error tells you something useful.