---
id: icloud.what-is-icloud-drive-on-a-mac
url: https://storagestudio.us/faq/icloud/what-is-icloud-drive-on-a-mac
category: "iCloud & iCloud Photos"
subcategory: "iCloud Drive basics"
question: "What is iCloud Drive on a Mac?"
alt_questions:
  - "How does iCloud Drive work on Mac?"
  - "What does iCloud Drive do?"
  - "icloud drive explained"
  - "Is iCloud Drive built into macOS?"
  - "Where is iCloud Drive in Finder?"
short_answer: "iCloud Drive is Apple's built-in file sync service. It appears in Finder's sidebar, keeps your files in iCloud across your devices, and can store them on your Mac or as online-only files that download when opened."
tags: ["icloud drive", "basics", "finder"]
related: ["https://storagestudio.us/faq/icloud/is-icloud-drive-a-backup", "https://storagestudio.us/faq/icloud/what-does-online-only-mean-for-icloud-files"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# What is iCloud Drive on a Mac?

iCloud Drive is Apple's file-storage service built into macOS. It keeps the files you put in it in iCloud and syncs them across your Mac, iPhone, iPad and iCloud.com. On a Mac it appears as **iCloud Drive** in Finder's sidebar.

Files in iCloud Drive can be downloaded (stored on your Mac) or online-only (stored in iCloud, downloaded when you open them). With **Optimize Mac Storage** on, macOS moves older files to online-only by itself when space runs low.

iCloud Drive is a sync service: deleting a file from it deletes it everywhere. It's not the same as a backup. Storage Studio works with iCloud Drive's folder on your Mac to make downloaded files online-only and to measure what iCloud uses. See [does Storage Studio work with iCloud Drive](https://storagestudio.us/faq/icloud/does-storage-studio-work-with-icloud-drive).