recruiters/headhunters are middleman. they get requests from a company and then search for qualified candidates, either in their resume pool or online. Once they filter through, they will send candidates to the hiring company for interview.

Yes. It doesn't hurt to talk to them as they may help you to find you a job. Typically recruiter interview is t

1. go over your resume, verifying what u wrote

2. check your personality, ask behavioral question.

They normally won't ask too many tech questions as they don't really know what to ask and the hiring company will interview you anyway.

And you can ask to re-arrange interview when they call. but you also need to go over ur resume and know what they talk about.