Skype is a software application that allows users to make voice calls over the internet. It is a very popular and powerful communication software. By early 2009, it had a daily presence of about 42 million people. One of the main reasons for the popularity of this service is the fact that calls between users is free. Only calls made to mobile and landline phones are charged a fee. Skype is very easy to use, with a large amount of options available for use, both during and not during chat. Here is a list of features available on skype that makes it powerful communication software:

* Calls: by using the "call" option, a user can call another user free of cost. Audio aids are required to be able to hear the speaker.
* Text chat: The software allows you to add as many friends as you want on the friends list. You can chat with those friends who are online. the chatting feature is easy to use and is similar to other popular chat platforms. You can either chat with one of your friends on the list or use the conference chat option and chat with multiple users simultaneously.
* Chat history: this feature allows you to retrieve the history of chat. Users can filter the history using based on the oldness of chat.
* Emote: there is an array of emotive icons available. You can use these icons to be more expressive while using text chat.
* Send files: sharing documents is one of the features that has made skype popular among corporate firms. You can either share a single document or multiple documents amidst users.
* Video chat/calls: you can make video call or video chat on skype. However you need a web camera to do this. The service is available free of cost.

Author Bio:
I am a programmer working in a conference call service providers company which provides several conference call services including audio conferencing services, video conferencing services and web conferencing services.