YouTube is written in python, so the code for the application on android and ios also consists of the same code as for the web?

Question

Mobile development

YouTube is written in python, so the code for the application on android and ios also consists of the same code as for the web?
Vk is written in php is it a mobile application too?

Answer 1

No. Python in these services is used for server-side processing (for example: login and password verification). To display the site itself on the Web, a markup language is used (usually HTML), on Android - Java, and on IOS - Swift

Answer 2

What's behind these conclusions? Of course not, they write on what they know better and what suits better. Otherwise, according to your logic, all sites should be written in the same language.
One YouTube probably uses more than one language, depending on the service or module.
Applications most often use some kind of internal or public api, in fact, like most services, so in general, you can write in almost any language that the device supports, be it an iPhone, Samsung or laptop.