Question

I know a little about it, was just curious to know more.

FileInputStream reads in raw bytes from a file, as opposed to the CharacterStreams FileReader which reads in streams of character.

RandomAccessFile supports both reading and writing, also provides a file pointer using which one can jump into any point in the file.

Scanner can be used to read in any input, even a file. It parses the input into tokens.

So which to use when?
Is Scanner limited to only text files and the other two can be used to read any file?

Answer 1

Scanner and FileReader are limited to text.

FileInputStream and RandomAccessFile are limited to binary (or ASCII text files)