Question

I understand that android is a completely different thing than browser programming.
But coming from a web development background, I wanted to undertand what fragments are supposed to be used for ?
Are they similar to the concept of iframes in an HTML page having its own UI and can be added to any other page?

If not then what is tje general use-case of android fragments ?

Answer 1

They are reusable parts of your applications. You can have for example two different Activities using same Fragment. You may want to read Fragments Design Philosophy in the android documentation.

Here’s also short description from the same documentation page:

A Fragment represents a behavior or a portion of user interface in an
Activity. You can combine multiple fragments in a single activity to
build a multi-pane UI and reuse a fragment in multiple activities. You
can think of a fragment as a modular section of an activity, which has
its own lifecycle, receives its own input events, and which you can
add or remove while the activity is running (sort of like a “sub
activity” that you can reuse in different activities).