The sheet owner and licensed collaborators with Admin access to the sheet can hide a column to remove it from view while still keeping its content available in the sheet.
TIP: Though this functionality isn't available for rows, you can apply a filter to the sheet to hide rows based on criteria they contain. The filter will impact only your view of the sheet and other collaborators can apply their own filters as needed.
IMPORTANT: Hiding is useful when your goal is to format the sheet such that it displays only the most relevant information. Hiding is not a security feature. While collaborators with Editor and Viewer access won't be able to unhide the columns within Smartsheet, they can export the sheet to Excel or send it as an Excel attachment and un-hide the columns from that program.
Hide a Column
To hide a single column, click the drop-down arrow beneath the column's header, or right-click on the column name, and select Hide Column.
To hide multiple columns, hold down the [Ctrl] (Windows) / [Cmd] (Mac) key as you single-click on the header of each column you want to hide. You can then click the drop-down arrow underneath any highlighted column's header and select Hide Column.
The sheet owner and Admins can unhide all columns by clicking the drop-down arrow beneath any column header and selecting Unhide All Columns. They can unhide a single column by click-and-dragging the double-bar (which represents a hidden column) in the column header.