Will Windows Phone 8 apps run on Windows 10 Mobile -

i searched couldn't find proper answer question.

will windows phone 8 application work on windows 10 (mobile), or need change code can make them work?

how windows phone 8.1 apps , universal apps?

thank all

microsoft moving paradigm windows app windows app regardless of if it's phone targeting app or not. you'll see lot of references "windows 10 apps" or "universal windows apps" or "uwp apps" new paradigm. means targeting windows 10 regardless of if it's on phone or tablet or desktop , doesn't have specific references phone.

if developed universal app you're go. windows phone 8 , windows phone 8.1 apps may (or may not) need make changes move toward universal type of app. depends little on how using silverlight (not it's not supported there changes you'll want test app).

this video blog (and comments below it) might explain difference between windows 8.1/8 phone apps , uwp. http://blogs.windows.com/buildingapps/2014/12/17/bring-your-windows-phone-silverlight-apps-to-windows-runtime-xaml-prepare-for-universal-app-development-in-windows-10/