The -r option in the sed command enables extended regular expressions. Here's a breakdown of the sed command and the -r option:

• sed: The stream editor utility for parsing and transforming text.
• -r: Enables extended regular expressions. In some versions of sed, this option is -E instead of -r.

With the -r option, you can use extended regular expressions in your sed commands.

Extended regular expressions provide additional functionality compared to basic regular expressions, such as:

• support for the + and ? quantifiers
• the use of parentheses for grouping expressions