Skype is a Voice over Internet Protocol (VOiP) service that you can set up on your PC to receive free calls from other Skype members. Once you download and install the Skype program on your PC, you can make and receive calls from other Skype members. Skype also allows you to send and receive text and instant messages, transfer files, screen share, and make conference and video calls. Skype offers both paid and free services.