Consider the following text file:

$ cat input4 8.10 8.5 8.1 8.01 8.010 8.100 8.49 Numerical Sort: Version Sort: $ sort -n input4 $ sort -V input4 8.01 8.01 8.010 8.1 8.1 8.5 8.10 8.010 8.100 8.10 8.49 8.49 8.5 8.100

Numeric sort (‘`sort -n`’) treats the entire string as a single numeric
value, and compares it to other values. For example, ‘`8.1`’, ‘`8.10`’ and
‘`8.100`’ are numerically equivalent, and are ordered together. Similarly,
‘`8.49`’ is numerically less than ‘`8.5`’, and appears before first.

Version sort (‘`sort -V`’) first breaks down the string into digit and
non-digit parts, and only then compares each part (see annotated
example in Version-sort ordering rules).

Comparing the string ‘`8.1`’ to ‘`8.01`’, first the
‘`8`’s are compared (and are identical), then the
dots (‘`.`’) are compared and are identical, and lastly the
remaining digits are compared numerically (‘`1`’ and ‘`01`’) –
which are numerically equal. Hence, ‘`8.01`’ and ‘`8.1`’
are grouped together.

Similarly, comparing ‘`8.5`’ to ‘`8.49`’ – the ‘`8`’
and ‘`.`’ parts are identical, then the numeric values ‘`5`’ and
‘`49`’ are compared. The resulting ‘`5`’ appears before ‘`49`’.

This sorting order (where ‘`8.5`’ comes before ‘`8.49`’) is common when
assigning versions to computer programs (while perhaps not intuitive
or “natural” for people).