What is the difference between Senior Web Developer position and Web Architect position?

After 12 years and lots of experince and success at my role as a senior web developer (client and server), I am now feeling ready for my next step in career – Web Architect. This is something
I really want for a long time.

This role is very rare position in the company (only few architect in the all company). All architect are old, while I’m only 30. Everyone around me agree the role fits for my skills, but there are few who said its not my time and I need more years and more experiance.
I was told I have not managed a lot of people cross teams, only memebers inside me team.

What are the important things you will be looking for in a candidate in that kind of a role?
How can I shine at this interview?