To see column titles

I am making a record file of books in a spreadsheet. Each column has its title, but as I scoll down they disappear. How can I keep them on top of the spreadsheet window?

Select cell A2 (or the first cell with data just under the titles)
Click on the menu Window, Freeze.

A grey line will appear under the titles.

From now on scrolling down will scroll through the data but the title line will always be visible.

So simpe! Thank you.

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