When creating large Microsoft Excel documents it can be useful to have certain columns or rows frozen in place to improve readability. In this example there are two similar cells lower in the document that require the reader to scroll back to the top of the document to understand what they are looking at.
With frozen panes, important reference panes remain in view for improved readability.
To freeze a pane: select the View tab >> select the cell(s) adjacent to the panes you want frozen >> click Freeze Panes in the menu bar
Visit the official Microsoft Excel support page for more information:Microsoft Office | Excel | Freeze Panes to Lock Rows and Columns