You may occasionally want to use its little brother, `sed`, which has substantially similar syntax. It is often the case in Unix programming that you have a pipe full of text data and you would like to transform every line of it; `sed` allows you to write these transforms into one line of instructions on the console line.

So it may sound crazy that you have all of these terse commands, but just imagine that you're trying to write a one-line program to reformat text documents and it suddenly makes a bit more sense.