1.Difference between Reader/Writer and InputStream/Output Stream?
The Reader/Writer class hierarchy is character-oriented, and the Input Stream/Output Stream class hierarchy is byte-oriented.
Basically there are two types of streams.Byte streams that are used to handle stream of bytes and character streams for handling streams of characters.In byte streams input/output streams are the abstract classes at the top of hierarchy,while writer/reader are abstract classes at the top of character streams hierarchy.
2.What an I/O filter?
An I/O filter is an object that reads from one stream and writes to another, usually altering the data in some way as it is passed from one stream to another.