An "update" is new information about something. For example, if your uncle is in the hospital for surgery, you can call another family member to get an "update" on his condition. Or if you've hired a realtor to help you sell your house, you might e-mail him to ask for an update if he hasn't contacted you for a few days.
To ask someone for an update, use the question:
Do you have any update on ___?
Or use the shortened version:
Any update on ___?
Any update on how uncle Harry is doing?
Do you have any update on whether you'll be attending the trade show yet?