Instant messaging is an online messaging service that allows you to message people instantly. The services that provide instant messaging are Facebook, Google, Twitter, Microsoft through skype and WhatsApp. Below is a screenshot of me using the instant messaging service WhatsApp:
WhatApp is an application which can only be downloaded onto smart mobile phone or similar devices. The application works over the internet and through your contacts so it is a free way of texting your phone contacts. The app shows you who else on your contacts has the app and then allows you to message them through it. You can also create group chats with multiple contacts so that you can communicate with multiple people at once. This chat also allows you to send photos and videos from your phone to one another.