Bondi's Mac guide

What is this process?

Spotted a name in Activity Monitor you don't recognise? Look it up here: what it does, why it gets busy, and whether you can quit it. Checked against real readings of a real Mac.

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apsdapsd is Apple's push notification service on your Mac. What it does, why it's rarely busy, and what to do when apsd asks for your keychain password.
backupdbackupd runs Time Machine backups on your Mac. Why it uses CPU during a backup, what backupd-helper is, and how to stop a backup safely.
clouddcloudd syncs your data with iCloud for Apple's apps and iCloud Drive. Why cloudd uses high CPU on a Mac, and what to do when a sync seems stuck.
CommCenterCommCenter handles phone calls and text messages that work with your iPhone on a Mac. Why it asks for your keychain, and whether CommCenter is a virus.
coreaudiodcoreaudiod handles all sound on your Mac. Why it uses CPU, how to restart coreaudiod when the sound stops or crackles, and why you shouldn't quit it.
fileproviderdfileproviderd connects iCloud Drive, OneDrive, Dropbox and other cloud storage to Finder. Why it uses high CPU or memory, especially while OneDrive syncs.
fseventsdfseventsd keeps a record of file changes for Time Machine, Spotlight and other apps. Why fseventsd uses CPU or memory during builds, downloads and unpacking.
launchdlaunchd is the first process macOS starts, and it starts every other service. Why launchd is rarely busy, and what high CPU from it usually means.
loginwindowloginwindow is your Mac's login session. Why loginwindow can use hundreds of MB of memory, what loginwindow Secure Input means, and why not to quit it.
mDNSRespondermDNSResponder finds devices on your network and looks up web addresses for every app. Why it uses network or CPU, how to restart it, and why not to disable it.
mds_storesmds_stores is Spotlight's indexer. Why it uses high CPU, memory or disk on your Mac, how long indexing takes, and how to keep folders out of it.
mdworkermdworker and mdworker_shared are Spotlight's helpers that read your files. Why there are many copies, why they use high CPU, and when they settle.
mediaanalysisdmediaanalysisd analyzes photos and videos on your Mac for search, Live Text and Visual Look Up. Why it uses CPU, memory and storage, and what to leave alone.
photoanalysisdphotoanalysisd analyzes your Photos library for people, places and Memories. Why it uses CPU after imports, and whether you can disable or stop it.
rapportdrapportd lets nearby Apple devices talk for Handoff and Continuity. Why it asks to accept connections, and whether to allow it.
spindumpspindump records what an app was doing when it stopped responding. Why it uses CPU right after a hang, and where its reports go.
syspolicydsyspolicyd is Gatekeeper: it checks apps the first time you open them. Why syspolicyd uses CPU on your Mac, and why it's busy for developers.
SystemUIServerSystemUIServer runs some of the menu bar's icons on your Mac. Why it's rarely busy, and how to restart it when menu bar icons stop responding.
trustdtrustd checks the security certificates of the websites and servers your apps connect to. Why trustd uses CPU on a Mac, and why several copies are normal.
WindowServerWindowServer draws everything on your Mac's screens. Why it uses CPU and memory, why it can keep a Mac awake, and whether you can quit it.
XProtectXProtect is Apple's built-in malware protection on every Mac. What XprotectService does, why it uses CPU, and why you should leave it running.