Skype is a company which is owned by microsoft. I have been using it for last 3 years almost and it gave satisfactory results.
this is the best video calling service I have ever used. two years ago I also used google hangout when I had to go to koimbatore, I tested hangout but the quality was not as good as skype. skype apps let you do video calling and voice calling without any interruption.
I have also heard that even the facebook video calling facility is not as good as skype.
it is very easy to use it. just download it free and create a free account and you are all set to do video calling with someone who also has skype account.
so just go for it without any second thought.