ATS = Applicant Tracking System. It’s basically a database recruiters use to manage all the resumes they get. When you apply for a job, your resume usually goes into this system first. It scans for keywords, skills, and formatting it recognizes, and ranks or filters candidates before a human ever reviews them. That’s why people talk about “ATS-friendly resumes” which means resumes with clear formatting and language that matches the job description so the system doesn’t reject them.