Mobile App Developer

Hello Anshuman,If you are really interested in technology, you can do courses like artificial intelligence, internet of things, virtual reality etc. From popular online courses portals like NPTEL, Udemy, Coursera, etc. There are many applications of these domains related to biology also. For example, Virtual Reality domain is widely applied in medicine, especially in surgical training, pain management, treatment for psychological diseases, rehabilitation, etc. And similarly, there are plenty of courses available for learning how to make blogs, videos. You can also start your own YouTube channel, to learn everything from making blogs to video editing. Best wishes.

Hello Ayush,
Facebook and WhatsApp aren't dependent on just one programming language, they involve many. A markup language for designing Front End user interface (probably XHTML/CSS), web programming to validate data (probably PHP), security validation for logins and privacy settings (probably JAVA servlets), a background database to store information (probably SQL/Oracle Database), a pipeline to connect the user interface to the database (probably JDBC/ODBC). Along with these, there could be many more programming languages being used as per the requirement.
Building such an application isn't the job of a single person. It involves a team in which there are members skilled in at least one of the languages being used in the application.
I hope I have been able to answer your queries to your satisfaction.
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