Ubuntu Diff Compare Files Side By Side

diff -y file1 file2
diff -ty file1 file2
diff -ty file1 file2 |cdiff
sdiff file1 file2 |cdiff

Show Only Difference

diff -y - --suppress-common-lines file1 file2 |cdiff

Use Full Teminal

diff -y -W $(tput cols) file1 file2 |cdiff

Note: cdiff requires colordiff to be installed.