In a legal context, there are rules about leading questions. As others pointed out, a leading question is one which suggests an specific answer to support a case or defense, and in the legal context, it is also one which challenges someone's answer. I'll give an example:
"You ignored the stop sign, didn't you?" <-- suggests the answer & supports the attorney's case.
In common-law jurisdictions, this kind of question is sometimes not allowed. This is because the question might manipulate the witness, or might influence the jury. In the United States, this comes under Federal Rule of Evidence 611(c).
They are not allowed under "direct examination" (when interviewing a "friendly witness" who has been called to support the attorney's case).
But they are allowed under "cross examination" (where the witness has been called to court by the opposite side) and also when asked of "hostile witnesses" (a witness who might not have been called by the opposite side, but who is uncooperative in some way to the attorney's side). And they are always allowed when asking for basic information that does not support either side (such as, "your name is John Smith, right?"