What Are the Functions of Skype?

Skype's most basic function -- and one that is free to use -- is computer-to-computer calls. After signing up for a Skype account and adding a user to your contact list, make a voice or video call to him simply by double-clicking his name and clicking "Call" or "Call With Video." Just as cellphone call quality varies depending on signal reception, the quality of Skype voice and video calls varies depending on the speed and quality of your Internet connection.

Another free Skype feature is text-based chat between users. Similar to instant messaging clients such as Windows Live Messenger and AIM, it's possible to chat with users in your Skype contacts list. After clicking the name of a user, type a message to him in the empty field at the bottom of the window that pops up and click "Enter." In addition to chatting within Skype itself, it's possible to chat via text with Skype contacts using a Web-based messenger such as "ILoveIM" or "imo.im."

Once you load credit into your "Skype Account" using a debit card, credit card or PayPal, it's possible to make phone calls to land lines and cellphones around the world, at rates that are fixed and generally low. To call a phone, click the "Call Phones" button at the bottom of your contact list, then enter the number in the window that pops up, making sure to select a country from the list of options, if you're calling internationally, before you click the "Call" button.

It's also possible to send text messages to cellphones around the world with Skype. After entering your phone number -- and country code, if necessary -- type a short message in the blank field at the bottom of the window, as you would do if you were chatting with someone. The difference in the "Call Phones" window is that the button next to the field says "SMS," and clicking it sends an SMS text message to your recipient. Skype notifies you when the text message has been delivered by showing the word "delivered" above the message.