The Silent Bandwidth Drain
By default, the macOS App Store attempts to keep all your installed software completely up to date. To ensure you always have the latest features and security patches, the operating system runs a background process that periodically checks Apple’s servers. If it finds new versions of your applications, macOS will automatically begin downloading these updates in the background. While convenient, this autonomous downloading can severely choke your internet connection if you are on a slow network, rapidly deplete your data cap if you are tethered to a mobile hotspot, and consume valuable processing power while you are trying to work on resource-intensive tasks.
Regaining Control of App Updates
To protect your bandwidth and stop macOS from automatically downloading large application updates in the background, you must modify the specific preferences within the App Store settings.
Click the Apple logo in the extreme top-left corner of your screen and select System Settings from the dropdown menu. In the left-hand sidebar, click on General. In the main right-hand panel, click on Software Update. Look for the section labelled “Automatic Updates” and click the small “i” (information) button located to the right of it. A new dialogue box will slide down. Look closely at the list of options for the toggle switch explicitly named Download new updates when available. Click this toggle to turn it Off. To be completely certain no App Store traffic occurs without your permission, you should also turn off the toggle for Install application updates from the App Store. Click Done to save your changes. You will now need to manually open the App Store app to initiate any downloads.