To merge and center cells in Excel, follow these steps:
Select the cells that you want to merge. You can do this by clicking and dragging across the cells, or by clicking on the first cell and holding the Shift key while clicking on the last cell.
With the cells selected, go to the "Home" tab on the Excel ribbon.
In the "Alignment" group, you will find a button that looks like a few merged cells with a centered arrow. This is the "Merge & Center" button. Click on it.
The selected cells will now be merged into a single cell, and the content will be centered within that merged cell.
Note: When you merge cells, the content of the top-left cell in the selected range will be preserved, and the content of the other cells in the range will be deleted. So, if you have important data in multiple cells, make sure to merge them carefully to avoid losing any information.