To demonstrate the work of the commands, we will create two binary files. Create file hello.c with the following contents:

#include <stdio.h>

int main(void) {
 printf("Hello world!\n");
 return(0);
}

then compile it

# gcc hello.c -o h1.bin
./h1.bin

Hello world!

Now make change in hello.c add !

...
printf("Hello world!!\n");
...

recompile it and run

# gcc hello.c -o h2.bin
./h1.bin

Hello world!!

Now we have two binary files, one of them print on standart output "Hello world!" second "Hello world!!"

ls -l

total 44
-rwxr-xr-x. 1 root root  8512 Jul  2 13:30 h1.bin
-rwxr-xr-x. 1 root root  8512 Jul  2 13:22 h2.bin
-rw-r--r--. 1 root root    79 Jul  2 13:21 hello.c

As you can see, they have a same size, but we execly know that they are different.

cmp
The cmp utility compares two files of any type byte by byte and writes the results to the standard output. By default, cmp is silent if the files are the same; if they differ, the byte and line number at which the first difference occurred is reported.

# cmp h1.bin h2.bin

h1.bin h2.bin differ: byte 645, line 1

The cmp command compares two files, and if they differ, tells the first byte and line number where they differ or reports that one file is a prefix of the other. Bytes and lines are numbered starting with 1.

Output of command can be more informable if you use some options:

# cmp -lb h1.bin h2.bin

645 265 M-5  225 M-^U
646 276 M->   12 ^J
647 247 M-'  177 ^?
648 327 M-W   71 9
649 122 R     45 %
650  27 ^W   221 M-^Q
651 246 M-&   13 ^K
652 152 j     10 ^H
653 263 M-3  364 M-t
654  55 -    216 M-^N
655   1 ^A    52 *
656 231 M-^Y 375 M-}
657 136 ^    213 M-^K
658  15 ^M   240 M-
660 271 M-9  334 M-\
661 327 M-W  106 F
662 254 M-,  302 M-B
663 173 {    226 M-^V
664  36 ^^   274 M-<
1517   0 ^@    41 !
7585  35 ^]    36 ^^

md5sum
Another simple way to compare two files is check MD5 (128-bit) checksums.

# md5sum h1.bin h2.bin

55bdf8972e7fb9464676c450a335d0a2  h1.bin
99f9015d8c4ac74d64cb7fd8cefd8c3f  h2.bin

diff
With some options you can yse diff command.

# diff -qs h1.bin h2.bin

Files h1.bin and h2.bin differ

# diff -qs h1.bin h1.bin

Files h1.bin and h1.bin are identical

CentOS 7

No features.

openSUSE Leap 42.3

No features.

Ubuntu 17.04

No features.