What is a bug?

In software development, a 'bug' refers to an error, flaw, or fault in a computer program that causes it to produce incorrect or unexpected results, or to behave in unintended ways. Bugs can arise from mistakes made by programmers, design errors, or unforeseen interactions within the code. Identifying and fixing bugs is a crucial part of the software development lifecycle, ensuring that applications work as intended and delivering a positive user experience.