Typically recruiters use a number of methods to attract suitable candidates for their clients.

Database.

Recruiters often run a database of candidates that have applied for role in the past and have not been able to find appropriate match. Databases are more often that not out of date and need constantly topping up

These candidates are actively looking to move.

Advertisements.

This is self explanitory, a recruiter will place an ad in a local or national newspaper, or even a trade publication.

The candidates that are attracted to the adverts are both people who are active and those who have not yet made that decision to move or not.

Research.

Research is a much more targeted approach.

A Research company will recieve a job brief, form a list of target companies, identify the potential candidates, approach these candidates and profile them with a view to gaining a CV.

The candidates that are produced from research can be actively looking, passively looking or not even looking at all.

It targets ALL of the potential workforce allowing you to take your pick from the best available.