The smallest unit in Coda is the row, as opposed to the cell in Excel. Working with rows, we're able to access all of the contextual details for each value (aka columns or attributes of the row). 

Try this in your own doc. Click into the canvas, then type @ and start typing the content within the display column if your row. 

Let's say we want to add an Assignee column to this Tasks table. You want to add a relation column to be able to select people from the Team table. Once you've added an Assignee, you're able to access any other data from the team table associated with that person's row. 

One common place you'll see it is within a relation column or a Filter. Here's an example: 

In table A, we have two categories: Fruit and Vegetable. In table B, we have a list of food, with a row attribute (column) denoting whether or not they are fruit or vegetables. thisRow allows us to pull in each of the food items to table A associated with the specific category value of each row. 

Of course, there are other use cases for thisRow! The takeaway is that it allows you to isolate one row from a column to perform a function on.