"Freezing", sometimes called "Locking", your rows is a great way to compare specific rows to the rest of your data.
In google sheets, when you lock a row, it will keep all of the data in and above that row visible as you scroll through the chart. Someone may lock a row in google sheets if they want to compare a certain segment of data to the rest of the table.
I will show you how to freeze any line in google sheets with these three simple steps.
Step #1: Select the R
First, you will click anywhere on the row that you want to freeze/lock.
You can also click and drag the grey bar at the bottom of the "A1" cell to select what rows are frozen, as well. You can lock any rows that you want thanks to google sheets.
Step #2: "View" --> "Freeze"
Next, simply open the "View" drop-down menu and select the "Freeze" tool. That will lead you to the second menu, which will let you specify how you want to freeze your rows.
Google lets you freeze multiple rows, and even freeze columns if you want to.
Alternatively, if you wan to unfreeze rows that were previously frozen, you can just follow the same steps, but select "unfreeze" to begin un-freezing rows/columns.
I usually like to select the "Up to Current Row" option.
Step #3: Make Sure it Works
Lastly, you will need to scroll through your data and verify that the freeze actually worked. As you can see in the example image, the row you froze will stay on screen as you scroll down, but the rest of the data will continue to scroll down normally.
And that is how you freeze rows in Google Sheets.