Few basic question about IONIC and mobile apps development

Question

1) what is IONIC

 

2) to develop application with ionic and visual studio developer need VS2015 or VS2013 also work ?

 

3) what is difference between ionic and phone gap

 

4) what is cordova and cortana ?

 

5) cordova and cortana has any relation with ionic ?

 

6) why ionic is called hybrid apps ?

 

7) why ionic is called hybrid apps ? 

 

8) what is the meaning of native apps regarding mobile development ?

 

9) when we develop mobile apps with ionic then how could we create setup file for all platform like windows phone, ios, android etc from VS2015 IDE ?

 

i do not have development background regarding mobile apps. i work as a web and windows developer using c#, winform, asp.net. i never develop any mobile apps. so please guide me answering my questions in details.

 

thanks