fsck

One of several ways -

1 - Restart the computer in Safe Mode and it does a Repair Disk. Safe mode may help you resolve or isolate problems that you’re having with your Mac. When you start up in safe mode, your Mac prevents some software, such as startup items, from loading, and it performs a check of your startup disk. Your Mac may take longer to start up because of the check.

2 - Restart the computer in Recovery Mode Command + r and in Disk Utilities run the " First Aid "

Is there a specific reason or need to run the fsck command ?

To see the usage of fsck - open the Terminal Application and type " man fsck " without the quotation marks.

Be very carful in the Terminal and commands used.

Command line is a very unforgiving place to work.

One small error could corrupt and or damage the Operating System to the point of having to Reinstall the OS from zero.

Welcome and Thank you too.

Do come back to the ASC Forums, in the future, if / or when additional question may arise