SQL Server Delete From vs. Truncate Table
There are some very important distinctions between these that I feel I need to explain.
First and foremost delete is used for deleting a limited number of rows from a table. This is not to be used for deleting all rows in a table.
Another important note is that this is a logged process meaning it writes this delete into the transaction log. Which is good if you ever need to recover those rows.
Also deleting rows does not reset or reseed, more technically, any identity columns. So deleting the last row will not decrement the identity column.
So this function is to delete all rows in the table.
Unlike Delete, this operation is very efficient, mainly because it is not a logged process. Use this for very specific reasons, testing, repeating processes, etc.
Also it will reseed the identity column in your table. So for example, it will delete all the rows in your table and the identity will be reset to its initial value, by default this is the number 1.