1. A voice recognition method of a mobile terminal in connection with a server, the method comprising: receiving a user's voice; providing the received voice to a first voice recognition engine provided in the server and a second voice recognition engine provided in the mobile terminal; acquiring first voice recognition data as a result of recognizing the received voice by the first voice recognition engine; acquiring second voice recognition data as a result of recognizing the received voice by the second voice recognition engine; estimating a function corresponding to the user's intention based on at least one of the first and the second voice recognition data; calculating a similarity between the first and the second voice recognition is data when personal information is required for the estimated function; and selecting either one of the first and the second voice recognition data based on the calculated similarity.