Using online chat systems is like having a phone conversation via your keyboard. Instead of saying your message out loud, you type it out. This means that certain programs or websites can provide rapid, direct and real-time communication. After e-mailing, chat systems are a hugely popular way of communicating online. This is hardly surprising, given that you can find someone to chat with about a huge number of topics, from relationship drama, school, and the hottest bands, to computers and other hobbies. And it has never been easier to meet people.

Instant messengers developed from online chat systems. Just like when chatting online, messages are exchanged instantly. As soon as a message is sent, it appears almost instantaneously on the recipient's device. This is why it is referred to as "instant" messaging, though this is normally left out of the name for the sake of simplicity.

In addition to pure text-based messages, images or audio files can also be sent via instant messengers, and video calling and group chats are also available. What's more, these messengers are not subject to the 160-character limit that applies to SMS text messages. And generally speaking, sending these messages does not incur any additional costs beyond the cost of the internet connection.