---
tag: 5CRJ2QY8MY
kind: concept
name: Fiber (mathematics)
aliases: [fiber-algebraic-geometry, fiber-naive-set-theory, fibre-mathematics]
sources:
  - wikipedia: en:6603892@r1376129895
    locator: Fiber (mathematics)
    note: adopted
    mention: wikipedia://en/6603892
    sections: [Summary]
same_as:
  wikidata: Q1640811
  wikipedia: Fiber (mathematics)
inventory: [R92ZNFEKV3]
---

## Summary

In mathematics, a **fiber** (US English) or **fibre** (British English) of a map or [[function|0EPAT51DXQ]] $f:X\to Y$ is an equivalence class in *X* for the relation of having the same image under *f*. If *y* is that image, then this fiber equals the inverse image $f^{-1}(y) = \{ x\in X : f(x) = y \}$ of $y$ and is called the fiber of *f* over *y*.