Definition
A talent pool gathers the people a company or agency wants to be able to re-contact: runner-up finalists, promising unsolicited applicants, former employees, profiles approached through sourcing. It is organized by skills, occupations or regions, and maintained over time.
Active pool or dormant pool
A pool only has value if it is kept up to date and used. Without upkeep, it becomes a dormant talent pool: thousands of profiles nobody opens. Two habits make the difference: searching the pool before every new job, and treating candidates well the first time, with an answer and honest feedback. A candidate left without news rarely replies next time.
Mind retention rules too: tell candidates how long their file is kept, and stick to it.
Concrete example
A staffing firm tags its finalists by occupation and region. When a client opens a logistics coordinator role in Mississauga, it checks that pool first, calls back two finalists from last year and presents a profile to the client within three days, without posting a job ad. The pool worked because those finalists had been answered properly the first time.