Google Hangouts is the successor of Google Talk, Google Voice and Google+ Messenger. With Hangouts you can chat and make video calls. Hangouts is integrated in Gmail and Google+ and can be used as a web service in your browser. There are also apps for Android and iOS.
Hangouts makes it possible to chat (including group conversations), make video calls (with ten people) and send photos to your contacts. Hangouts is directly competing with Skype from Microsoft (which also has chat and video calls) and to a lesser extent with WhatsApp which is purely a chat service for smartphones.
The advantage of Hangouts - which means something like hanging out - over WhatsApp is that you can use the app on phones and tablets (iOS and Android). You can search for friends by name, e-mail address or telephone number. If they don't have Hangouts yet, they will receive an invitation.
Hangouts works on smartphones, tablets and PCs and can be used on iPhone, iPad, Android phones and tablets and as a web service in Gmail and Google+ your browser (for which you must first install a plugin). There has also been a separate site for the Hangouts web service since August 2015, accessible via: hangouts.google.com.
You can free download Hangouts 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.