How to show or hide columns in SharePoint Online List Library from

Until the SharePoint Modern Interface arrived, developers had to create custom forms in order to hide or show fields to users.
Say a column like "delay in approval" for admins to know how many days have crossed after the due date, this need not be shown to the end users on the request form. Options like InfoPath, jQuery/JavaScript, PowerApps, Spfx were used to hide the field from users on the form.

Now, SharePoint gives you an OOTB (Out Of The Box) way to show/hide selected fields on SharePoint List or Document Library forms - New, Edit, Display. The data in the column is not impacted, just its visibility on the form.

✔️ Steps to show or hide a field in list or library form

1. Navigate to your respective list or library.
2. Click and open any List Item (or document properties) to view the Display form. You can also use the New form.
3. Click "Edit form" from the top right corner of the form.
4. Click "Edit Columns".
5. Check/Uncheck to show or hide the column.
6. Click Save.

⭐ Points to consider

• The show/hide applies to all 3 forms - New, Edit, Display.
• Columns which are Required/Mandatory cannot be hidden.
• Columns with conditional formulas cannot be hidden.
• Hold and drag-drop up and down to reorder columns, or click on the 3 dots towards the right and move the column up or down. This will rearrange columns on all 3 forms. refer steps here.
• To show or hide columns in SharePoint views, do it from the respective view. Make sure you apply it on a public view if it is for all users.