Turn off Skype

So what does it have to do with an iPad (the forum you posted in)?

Skype is not installed by default on a Mac (or iPad for that matter) as it is a Microsoft product. If you don't use it, uninstall it, though not sure why you would have installed it if you don't use it.

How can I completely uninstall, and then reinstall Skype for Mac OS X? | Skype Support

You can simply disable Skype from your login startup items in Skype's settings. Or just delete Skype altogether. Skype is Microsoft's tool. If you ever need or want it again, just download it from Microsoft's online Store.

If you have MS Office 365 installed, it was part of that installer, but you are not obligated to keep it and removing it will not alter any of the other tools in Office365.