IPA: /ˈtrækər/
KK: /ˈtrækər/
A person or device that follows or monitors something, often used in technology or music composition.
The fitness tracker helped me keep track of my daily steps and calories burned.
Tracker → It is formed from "track" (from Old French *trac*, meaning a path or trace) and "-er" (meaning a person who). A tracker is a person who follows or traces a path.
Think of someone who follows a 'path' ('track') — the '-er' just means a person. A tracker is someone who traces a path.