It takes lengthy time to send an email in Gmail, so Gmail came up with inbuilt chat feature known as hangout. In hangout you can send messages easily without any delay to anyone provided that you know the username of the specific user. Hangouts provide you to chat via: text, video and phone.
How to chat in gmail
You just follow these simple steps:
1. Sign in your Gmail account.
2. The chat box will be shown on the left side of your Gmail home page.
3. Search the name of the user and send a message request to which you want to chat.
4. If user would accept your message request, then you’ll be able to chat.
5. Write a text and send to the user.