Here's the first time it mentions the word "content." I'm assuming that this is the definition it uses throughout:
"You may not submit or publish through the Skype Education Portal any text, sounds, pictures, photos, video, hypertext links and/or any type of information, comments, suggestions or ideas (“Content”) that: (a) is libellous, defamatory...."
Later in the agreement, it says the following about your content:
"You hereby grant Skype, its affiliates and agents a non-exclusive, worldwide, perpetual, irrevocable, royalty-free, sub-licensable and transferable licence to use, reproduce, distribute, modify, adapt, translate, publicly display and perform and create derivative works from and display the Content in any media for any purpose. You hereby waive any and all moral rights (including rights to attribution) that you may have in any Content."