de-identification: it is a method of data privacy protection, which reduces the relevance of data to a specific individual by removing or replacing sensitive personal identity information. De-identification is a technical means to protect personal privacy. Common methods include anonymization, encryption and desensitization. The goal of de-identification is to make the original data can not be traced back to the specific personal identity, thus protecting personal privacy.

de-tagging: it refers to the process of removing identifiable and traceable elements such as tags, labels or comments from pictures or documents. The purpose of unmarking is to eliminate or blur some specific marks, so as to make the information more universal and without personal or specific marks.