An Applicant Tracking System (ATS) is like a digital organizer for hiring people. Recruiters post job ads in the system, which then spreads them around the internet. People apply online, and their resumes are automatically sorted by the system. Recruiters can then look at these resumes and decide who to interview. The system helps with scheduling interviews and keeping track of where each candidate is in the hiring process. It also helps recruiters communicate with applicants and work together as a team. Overall, it makes hiring easier and more organized.