Guys there are many Web development technologies like PHP, ASP .NET, WEB 2.0, JAVA J2EE Architecture, Mobile Development, etc; but which is the most demanding in near future. which is good if I got to earn more and which is good in terms of security.

honestly that depends on where you live.

Where I live .NET is THE technology of choice, though in other places Java is the hot technology. So learn as much as you can.

I first started off with PHP, but I know several other languages as I didn't want to be limited in my skill set. The nice part is once you know a C-based language, the others will be a quick pick-up in terms of syntax handling.

Meh, professionally I'm a .NET (C#) developer and it isn't all its cracked up to be. At work, I do a lot of work in ASP.NET using C# with SQL Server.

I PREFER PHP and MySQL (or mariadb) as I am a C/99 coder at heart.

I don't get into the higher level stuff (some of the frameworks built on PHP for instance) but they are probably the way to go if you want to get into pro development. Laravel comes to mind. There are others.

On our forums, I have the honor of hosting the servers (for redundancy) and maintaining the full stack of technologies from the network to the server to the code itself. Yes, I have gig fiber and 4G dualies for backup, a Generac and all that jazz.