Google Hangouts is an instant messenger, video conference and remote tool that can run on different devices. Includes important features such as chat, screenshare, video capture/recording.
Users can share or use documents and files from Google Drive. Allows to use high quality video settings such as HD, you can limit internet bandwidth used by this application.
Invite users and talk to them using microphone, use webcam for video conferences. Discuss in a private group chat that you create or join other chat groups created by your friends. Allows to add third party effects and plugins. You can control other computers, with their permissions, and give them technical assistance, make trainings etc.