You hear your Mac's fans running, so you check Activity Monitor. Turns out something called "installd" is taking up a bunch of CPU power. What's going on?

Related: What Is This Process and Why Is It Running on My Mac?

This article is part of our ongoing series explaining various processes found in Activity Monitor, like kernel_taskhiddmdsworker, and many others. Don’t know what those services are? Better start reading!

Basically your Mac is installing, updating, or deleting a program. The process "installd", like most processes with a "d" at the end, is a daemon, which means it runs in the background and handles system functions. This particular daemon handles installing and updating applications found in the Mac App Store, along with updates to the operating system itself.

If you recently clicked "Install" in the Mac App Store, you're going to see installd running. The same is true if you uninstalled a Mac app downloaded from the Store: installd also handles removing such applications.

If you haven't installed or deleted any applications, installd is likely running because of an update. If you want to see what's being updated, you can head to the Mac App Store, then to the "Updates" tab.

You'll see a list of the updates currently being processed. Most of the time installd will finish the job after a couple of minutes. The only real exception is when Apple updates a bunch of large applications at once---the iWork suite, for example. When that happens, installd might run for a while. How long depends on your CPU and hard drive speeds, but on a modern Mac, installd probably shouldn't stay running for more than ten minutes or so.

By default, such updates are installed automatically---if you don't like this, you can control which updates are installed when in System Preferences under App Store.

We don't recommend turning off automatic updates, however: they're essential for protecting your Mac from malware and other potential problems. If you absolutely must turn these off, you can see a tally of pending updates by clicking the Apple logo on your menu bar: the number of updates available will be listed next to the words "App Store." Be sure to update regularly.

If you'd rather not launch the App Store to install things, you can update Mac App Store software from the Terminal. It's a lot faster, and just plain cool. It's easier to keep automatic updates running: that way you won't forget to install them. But if you want control, you've got options.