When you open a Google sheet, by default, the sheet comes with the gridlines, which is the same as the Microsoft Excel spreadsheets. Please see below how to hide or show the gridlines:
Step 1: Open a Google sheet and click any cell in the sheet;
Step 2: Click the "View" tab from the ribbon;
Step 3: Click "Gridlines" in the drop-down list;
Step 4: The gridlines will disappear.
To bring back the gridlines to the sheet, please repeat the same steps.
– If there is a checkmark in front of the "Gridlines", the gridlines show in the Google sheets.
– If there is no checkmark in front of the "Gridlines", the gridlines hide in the Google sheets.
If you work with Microsoft Word or Excel, please check how to show or hide gridlines here. The steps are the same.