Install Diffutils by running the following commands:
./configure --prefix=/usr &&
make &&
make install
The Diffutils package contains the cmp, diff, diff3 and sdiff programs.
cmp and diff both compare two files and report their differences. Both programs have extra options which compare files in different situations.
The difference between diff and diff3 is that diff comprares 2 files, diff3 compares 3 files.
sdiff merges two two files and interactively outputs the results.