---
tag: 1A5WRCNTM3
kind: concept
name: Link
msc: [57K10]
sources:
  - url: https://en.wikipedia.org/wiki/Link_(knot_theory)
same_as:
  wikidata: Q1760728
  wikipedia: Link (knot theory)
---

## Summary

A link is a finite collection of disjoint closed curves in three-dimensional space, considered up to deformation of the space.
Each curve is a component, and a link with one component is a [[knot|QYEAZTYGPT]].
Links show phenomena that single knots cannot, such as two components that cannot be pulled apart although each is unknotted.

## Explanations

### L1 human

Take several closed loops of string, possibly tangled together.
The [[Hopf link|JMWHKWD7EX]] is two rings linked like the links of a chain.
The [[Borromean rings|WX1Z2F3DCB]] are three rings that hold together although no two of them are linked.
Two links are the same if one can be moved to the other without cutting any string.