What is difference between busy and not interested?

Busy means being occupied or engaged in some work or activity which is important and requires full attention. It implies that the person is not available to engage in any other task or conversation at the moment but may be free later.

On the other hand, not interested means having no desire or enthusiasm in a particular task, topic, or conversation. It implies that the person has no intention or willingness to engage in any activity or conversation related to the topic or task.

The key difference between the two is that being busy indicates a lack of time, while not interested indicates a lack of interest or motivation. People who are busy may be interested in the task but may have other things that need to be attended to. Whereas people who are not interested may have the time, but lack the motivation to engage in the activity or conversation.

In short, busy is a temporary situation that can change, whereas not interested is a more permanent state of mind.