It aggregates jobs from multiple job boards, scans for relevant emails in job descriptions and on company websites and then allows you to apply to those jobs by clicking Apply. When you do that, an email from your own gmail account will be sent to those companies, so from their perspective, it's just an ordinary email. The result for a job seeker is saved time by not having to register to each job board and go through a tedious process of filling up different forms for each and every job. Just one click and you're done.