what is "indirect Wh Question"

if any one find the answear reply to me plz. plz some one send me message iam new in here. if some one know about this grammar that i asked reply to me

Hello, Azimhamid.

When you write a post, please put all relevant information within the message, because the subject line does not appear in the screen when someone is writing a reply.

Here are some indirect ‘Wh-’ questions:

Do you know who is coming to dinner?
Could you tell me where I can find the toy department?
I wonder if you can let me know when the washing machine finishes?

(This last one may be argued by some grammarians, but I feel it should end with a question mark.)