---
type: "concept"
title: "Open set"
slug: "open-set"
language: "en"
translationGroupId: "cmrez56ht0001qh015nhl0bt5"
domain: "General topology"
status: "usable"
aliases: ["Open subset"]
lastEditedBy: "ancient-tree"
---

An open set is an element of a [[topology|topology]].