A defect is a flaw in a component or system that can cause the component or system to fail to perform its required function. A defect can cause harm to the end customer, the company, or both, depending on the impact and severity of the failure. In this case, the defect in the code causes the system to lock down accounts that have an overdraft higher than $1000, instead of $10,000. This can cause harm to the end customer, as they may lose access to their funds and face inconvenience or financial difficulties. This can also cause harm to the company, as they may lose customer trust and satisfaction, face legal issues or complaints, or incur additional costs for fixing the defect and restoring the accounts. Verified References: [A Study Guide to the ISTQB Foundation Level 2018 Syllabus - Springer], Chapter 1, page 3-4.