Here are some screenshots of how I use the File Task.

First I have ForEach loop that will scan a folder looking for files matching a prefix. Here I'm using variables for folder path, file mask (ForEach1.jpg) and to capture the names of each file found in another variable (ForaEach2.jpg). Inside the ForEach loop I have the File Task that will move a file using the "Move File" operation (FileTask1.jpg). You could also use the "Rename File" to move a file if you need to rename the file as you move it (e.g. add a time stamp to the file name).