1. A method, comprising: in response to a human or machine identification request sent by a client, sending information pertaining to a first operation configured to identify human or machine to the client to be displayed; receiving a second operation that is submitted by the client, the second operation being triggered in response to an interactive operation performed on an operation track associated with the first operation; and identifying a triggering entity for the second operation as either a human or a machine based on a behavior characteristic model, wherein the behavior characteristic model includes a classifier for human operations and machine operations, and the classifier is trained based on operation samples.