This summary is not the rule. The rule text controls.
When a case involves something complicated, like medical issues, engineering problems, or financial details, judges and juries often need help understanding it. That's where expert witnesses come in. These are people who have special knowledge, training, or experience in a specific field.
An expert can share their opinion in court, but only if it will really help the judge or jury understand the evidence or figure out an important fact in the case. Someone can qualify as an expert in different ways. They might have studied the subject in school, worked in the field for years, received special training, or gained skill through hands on experience. There's no single path to becoming an expert witness.
The key point is that the expert's testimony has to actually be useful. If their specialized knowledge won't genuinely help the judge or jury understand something, then it doesn't belong in the case, even if the person is a real expert in their field.