Sure I can explain it better, hopefully.
If you do a google search for LINQ or lambda you will find expressions like this in either C# or vb.net (UiPath uses vb.net).
To explain it simply, it goes through each item in the List whether it’s datarows in a datatable or items in an array, which both work.
.Where(Function(row) … ) tells it to go through each item using the variable name of your choice (in this case I used “row” as my own choice)
and only keep the items that meet your specified criteria like row(1).ToString = “**”
Then you end with either .ToArray or .CopyToDataTable to set the list back to your desired type.
It should only find the rows that meet your criteria condition, so if it found something wrong then check your data or condition.
If there are multiple rows that meet your condition and you only want the first one, then add (0) on the end and it will only take 1 datarow.