# MATLAB: Can anybody help in understanding fopen and fread

file i/o

As per my understanding, fopen open the file in a mode which we want. For example, if we say r,then it opens in read mode. fread, read the open file and returns the no of elements.
Based on above line, i tried below code.
f= fopen('train-images-idx3-ubyte', 'r')Ans:f =      56
Here what 56 represents? I understand it is file identifier. How it is generated?
[a, count]= fread(f,4,'int 32')a =     1.0e+09 *      0.0509      1.6259      0.4698      0.4698count =       4
Could anybody help me to understand the above result.