When using macOS, you certainly know if you’ve opened a Pages file or are editing an email. But, below the surface are files that macOS uses that you don’t see all the activity required for background processes, Time Machine backups, Spotlight indexing, and other system needs. When you want to eject a mounted volume, like a volume on an external SSD or hard drive, you can run afoul of macOS’s hidden needs.

You can try to eject a volume normally in these ways:

• Select it in the Finder and press Command-E
• Select it in the Finder and choose File > Eject
• Control-click/right-click the volume in the Finder and choose Eject

If you’re lucky, when you try to eject a volume, you will see a message with specific details, such as: The disk "My Photos" couldn't be ejected because "Adobe Photoshop 2024" is using it. Quitting Adobe Photoshop will let you eject “My Photos”, but if there’s something happening at a system level, you will see a message worded like this: The disk "My Photos" wasn’t ejected because one or more programs may be using it. You can try to eject the disk again or click Force Eject to eject it immediately. Cancel and Force Eject buttons are part of the dialog, and a progress spinner appears next to the phrase “Trying to eject.”. That does not help resolve the situation. Here’s what you can do to narrow down the problem:

Close Finder windows. As odd as it seems, sometimes merely having a window open in the Finder that shows the contents of the volume or a folder on it may make the Finder believe that a “program” is using that mounted item. Close the Finder window and try again.

Remove the volume from Spotlight. I’ve found that Spotlight can sometimes seize hold of a volume and mark it as unejectable even when indexing isn’t actively in process on that volume. You can check if that’s the problem by going to Apple menu  > System Settings... > Siri & Spotlight, scrolling down to the bottom of the view, and clicking Spotlight Privacy. Drag the volume into the window (or click + and navigate to it, then add it), and click Done. This immediately removes the volume from indexing. Try to eject now. If it works, that was the problem. However, if you want to search items on that volume, you will need to remove it from Spotlight Privacy later.

Check if Time Machine is backing up. If Time Machine is actively backing up the volume, you may be unable to eject it. Check the status of Time Machine either through its system menu or by going to Apple menu  > System Settings... > General > Time Machine. If it’s underway, you can choose Skip This Backup from the Time Machine system menu or click the “x” box next to the active session in the System Settings view and wait for Time Machine to wind down. You can exclude the volume from Time Machine by using the settings view: click Options, click the + (plus) sign at the bottom of Exclude from Backups, and add the volume while mounted. Click Done.

Shut down. For a physically connected external volume, choose Apple menu  > Shut Down. When your Mac is completely shut down, unplug the SSD or HDD. Press the power button on your Mac to start up. For a “logically” mounted volume, such as a disk image or networked volume, choose Apple menu  > Restart. On restart, the volume should be unmounted by default. If not, immediately select it and use an eject option listed above, which should now work.

A battery’s lifespan is related to its chemical age, which is more than just the length of time since the battery was assembled. A battery's chemical age results from a complex combination of factors, including temperature history and charging pattern. All rechargeable batteries are consumable components that become less effective as they chemically age. As lithium-ion batteries chemically age, the amount of charge they can hold diminishes, resulting in reduced battery life and reduced peak performance.

Optimized Battery Charging is designed to reduce the wear on your battery and improve its lifespan by reducing the time that your Mac spends fully charged. It uses on-device machine learning to learn your daily charging routine so that it can delay charging past 80% in certain situations, such as when it predicts that your Mac will be connected to power for an extended period of time. Optimized Battery Charging aims to ensure that your Mac is fully charged by the time it expects you to need a full charge. To limit what your Mac considers a full charge, on macOS Tahoe 26.4 or later, you can also set a Charge Limit (see below).

When charging past 80% is delayed by this feature, "Charging On Hold" appears in the battery status menu. If you need your Mac to be charged to 100% sooner, choose "Charge to Full Now" from the menu.

To turn this feature off or on, use the Optimized Battery Charging setting in Battery settings. For example, in macOS Ventura 13 or later:

• From the Apple menu , choose System Settings
• Click Battery in the sidebar
• Click the info button next to Charging (or Battery Health)
• Turn Optimized Battery Charging off or on (when you turn it off, you can choose whether to turn it off only until tomorrow)
• Click Done

Whether using Optimized Battery Charging or Charge Limit, your Mac will occasionally charge to 100% to maintain accurate battery state-of-charge estimates.

Use Charge Limit to set a limit on what your Mac considers a full charge. Your Mac will charge to within a few percentage points of the charge limit, then stop charging and show "Charged to [%] Limit" in the battery status menu. If the battery charge level drops more than 5% while connected to power, charging resumes, again charging to within a few percentage points of the limit.

If your Mac is charged to the limit but you need it to be charged to 100%, choose "Charge to Full Now" from the battery status menu.

To set a charge limit:

• From the Apple menu , choose System Settings
• Click Battery in the sidebar
• Click the info button next to Charging
• Choose a Charge Limit setting between 80% and 100%
• Click Done

A version is saved automatically every hour, or more frequently when you’re making many changes, when you open, save, duplicate, lock, rename, or revert a document. You can also explicitly save a version.

To browse, restore, duplicate, and delete versions:

1. Open the document, then choose File > Revert To > Browse All Versions.

2. Click tick marks along the timeline to browse versions.

3. Display the version you want, then do one of the following:

• Restore your document to this version: Click Restore
• Duplicate this version in a new document: Press and hold the Option key, then click Restore a Copy
• Delete this version: Move the pointer to the top of the screen to show the menu bar, then choose File > Revert To > Delete This Version
• Leave your document as is: Click Done

To revert a document to the last opened version:

Open the document, choose File > Revert To, then choose Last Opened, Last Saved, or Previous Save

To explicitly save a version:

Open the document, then choose File > Save. To save the document using a different filename, location, or format, press and hold the Option key, then choose File > Save As

Your Mac includes a built-in tool called Apple Diagnostics (formerly called Apple Hardware Test). This tool will be handy if you are dealing with a hardware issue and not a software issue. You can use it to find and diagnose issues with your Mac’s internal hardware such as the Wi-Fi hardware, the Bluetooth hardware, Touch ID, the fan, or the power adapter, etc.

Prepare your Mac

• If you can install the latest macOS updates (https://support.apple.com/en-us/108382)
• Disconnect all external devices except keyboard, mouse, display, Ethernet connection and connection to AC power
• Determine if you have an Apple silicon Mac or an Intel Mac, go to the  Apple menu > About This Mac to find out (on a Mac with Apple silicon, About This Mac shows an item labeled Chip, followed by the name of the chip, on an Intel-based Mac, About This Mac shows an item labeled Processor, followed by the name of an Intel processor)
• Shut down your Mac (if you can't shut it down normally, press and hold its power button for up to 10 seconds, until your Mac turns off - every Mac has a power button; on laptop computers that have Touch ID, press and hold the Touch ID button)
• Turn off your Mac, then wait a few seconds for your Mac to completely turn off

On an Apple silicon Mac

• Press and hold the power button on your Mac (on laptop computers that have Touch ID, press and hold Touch ID)

• As you continue to hold the power button, your Mac turns on and loads startup options

• When you see Options, release the power button

• Press and hold Command (⌘)-D on your keyboard until your Mac restarts

On an Intel Mac

• Turn on your Mac, then immediately press and hold the D key on your keyboard as your Mac starts up (if using the D key doesn't work, press and hold Option (⌥)-D at startup instead)

• Release the key when you see a progress bar or you're asked to choose a language

Run Apple Diagnostics

Follow the onscreen instructions, which vary based on your Mac, the version of macOS that it’s using, and whether certain parts of your Mac have been repaired or replaced.

As you follow the onscreen instructions:

• If your Mac isn’t already connected to the internet, you’re asked to choose a Wi-Fi network, or you can use an Ethernet cable to connect to your network

• If asked to review terms and conditions, you might be given the option to run diagnostics offline (in that case, click Run Offline)

• In macOS Tahoe 26 and later, you’re asked to choose a specific diagnostic to run, such as a diagnostic for your built-in display, keyboard, or trackpad; in earlier versions of macOS, this is automatic

When testing is complete, Apple Diagnostics shows the results. If you see one or more reference codes and need more explanation, refer to the list of Apple Diagnostics reference codes (https://support.apple.com/en-us/102334).

If you can't use this information to resolve the issue on your own, you might need service (https://getsupport.apple.com/?caller=kbase). Provide the reference code you receive from the test when taking your Mac to an Apple Authorized Service Provider, Apple Store, or an Independent Repair Provider. Genuine Apple parts are also available for out-of-warranty repairs through Self Service Repair (https://support.apple.com/self-service-repair).

• Open "System Settings..." from the  Apple menu
• Go to "Keyboard"
• Click on the "Text Replacements..." button
• Adjust text to replace with a symbol or add more text to replace by hitting the plus (+) button
• Click "Done"

For example, if you set "JS" to be replaced with "John Smith", anytime you type JS and hit space the text will be replaced.