Something called storedownloadd is taking up a lot of CPU power, which you noticed while using Activity Monitor. Don't panic: it's just the Mac App Store downloading some software for you.

This article is part of our ongoing series explaining various processes found in Activity Monitor, like kernel_task, hidd, mdsworker, installd, WindowServer, blued, launchd, backup, opendirectoryd, and many others. Don’t know what those services are? Better start reading!

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

Today's process, storedownloadd, is a daemon, which means it runs in the background in macOS. This specific daemon handles downloads for the Mac App Store.

The name itself makes this obvious, but there are a few more pieces of evidence. First, resource usage only really happens when you're downloading something, be it an application you've chosen to download in the Store or an update for an app you already have.

Another hint: the process itself lives in

        /System/Library/PrivateFrameworks/CommerceKit.framework/Versions/A/Resources/
    

, a folder that also holds other processes related to the Mac App Store---like installd and commerce.

This process shouldn't use system resources unless it's actively downloading an application. You can check current downloads by opening the Mac App Store, and then checking the "Updates" section.

We've written about how to control when macOS updates are installed, if you'd like more control over when storedownloadd runs and takes up your system resources. Just remember to keep your software up-do-date, even with automatic updates turned off.