java streams

hi i find handling streams in java little complex...........

I want to know what the following codes doing .....

File f = new File("Students.txt");

FileInputStream fis = new FileInputStream(f);

BufferedInputStream bis = new BufferedInputStream(fis);

DataInputStream dis = new DataInputStream(bis);

[337 byte] By [Sundar.nagarathinama] at [2007-11-26 18:15:39]