Ionic 2 SRC folder


I’ve been using Ionic1 for 2 years and just trying to put hands on Ionic 2
but unfortunately ran into a problem that seems to be very small and i.e
When I edit content in WWW it reflects in browser through "ionic serve"
but after adding platform E.g iOS I found no SRC folder in to modify my apps content
please guide me as how to change content when in development environment rather than UI (ionic serve)