Can I call my friends abroad with skype?

Can I call my friends abroad with skype? Yes.

Skype to Skype calls are free anywhere in the world. You can also call from Skype to someone on their mobile or landline with a subscription or Skype Credit; and from any phone with Skype to Go. 

How do I make a call on Skype? You do following steps below:

Find the person or group you want to call from your contact list, or use Search. Select the contact you want to call, and then...

Step 1:
Make an audio call: Select the call button .

Step 2:
Make a video call: Select the video call button . 

Step 3:
Make a group call: Select the new icon (or menu button on Android) to Add participants, then select the call or video button. Select the group avatar to create a name for your group or to add a group picture.
At the end of your call, select the end call button to hang up.