National Information Exchange Model (NIEM) is a way for governments and organizations to share information between their systems in a secure and organized way. It's like setting up a big online clubhouse, where lots of different people with different ideas can get together and talk. All the information they share is kept in a secure place and is organized in a way that makes sense. The goal of NIEM is to help governments (both federal and state) and organizations work together more efficiently and securely.