The fill handle is very useful to copy formulas as you know but also, you can fill series of number or date. Look at the following tutorials to see what you can do.
Fill series of numbers
When you have to create a list of number, it is not necessary to create a formula or to write each number of your series one by one.
What you need is to write the 2 first numbers of your list and Excel will extend your selection. Have a look on this video to see how it works with positives, negatives and decimal numbers.
Fill series for thousands of data
If you have to create a big list of number (let say 5000), use the fill handle is not useful because it takes too much time.
It's better to use the tool Fill (Home>Fill). See this short video to see how to fill a big list of numbers.
Fill a series of date
Like for the number, It is possible to increase a series of dates very easily. But with the dates, there is something special
If you want to keep the same gap between your days, Excel understand what is your gap. If you want to keep the same gap between days for a week of for a month, it's not a problem for Excel. 😍👍
Have a look at this video to see how to fill series of days, month, weekdays with the fill-handle.
Fill a series of Text for the date
You can also fill series of Text day and Text month with the fill-handle: January, February, ...
You can also create your own list of data and add it in the setting of Excel. Like this, you can create any list of days of months for any langage in the same worksheet 😉