The Art of LEGO MINDSTORMS NXT-G Programming

conclusion

Files allow you to save data from you program onto the NXT. You can then use that data later in the program, the next time the program runs, or from a different program. The File Access block contains all the features you need to create a file, write and read data, or delete a file.

The Memory tab on the NXT window lets you manage the files on your NXT (either programs or data files). From this window, you can delete files to make room for other programs and transfer files between the NXT and your computer.