What language is used to describe the appearance of mobile applications?

Question

Mobile development

Essence of the question: the appearance of the site is described by CSS, and the appearance of mobile applications is described in what language?

Answer 1

XML in ios and in android, but there are visual editors built into ide (android studio, xcode), it is convenient to work with them

Answer 2

I also worked with android studio, in principle it is easy and really convenient