Here's how to use data validation to restrict data entry to specific items from a list in Excel:

1. Select the cells:
Choose the cell(s) where you want to allow users to select data from a dropdown list.

2. Open Data Validation: Navigate to the "Data" tab on the Excel ribbon. In the "Data Tools" group, click "Data Validation."

3. Set Allow to List: In the "Settings" tab of the Data Validation window, under "Allow," choose "List" from the dropdown menu.

4. Define the Source: There are two ways to specify the list of valid options:

- Directly enter the list: In the "Source" box, type your list items separated by commas. For example, "Apple,Orange,Banana."
- Reference the list location: Click the small dropdown arrow next to the "Source" box and select the cell range containing your dropdown options.

5. Additional Options (Optional):

- Ignore blank: Check this box if you want to allow users to leave the cell empty.
- In-cell dropdown: Check this box to display a small down arrow within the cell for easier access to the dropdown list.

6. Click OK: Once you've defined your settings, click "OK" to close the Data Validation window.

Now, when users click on the cell, they will see a dropdown list containing only the options you specified. They can only choose one of those items to enter into the cell. This helps ensure data consistency and prevents typos or invalid entries.