Reversing text sounds like a novelty, and sometimes it is. But there are four distinct ways to reverse a piece of text, and each one has a genuine use that the others do not cover.
The four modes
Reverse characters flips the entire string end to end. hello world becomes dlrow olleh. This is what most people mean by reversing text, and it is the mode behind puzzle-making, palindrome checking, and a certain amount of harmless mischief.
Reverse word order keeps each word intact but reverses their sequence. the quick brown fox becomes fox brown quick the. Spacing is preserved as it was, so the result stays readable rather than collapsing into a single run.
Reverse line order flips a list upside down. The last line becomes the first. This is the one with the most practical value: log files written newest-last become newest-first, chronological lists become reverse-chronological, and a sorted list can be flipped without re-sorting it.
Reverse each word is the odd one out. It flips the letters inside every word while leaving the words themselves in place. hello world becomes olleh dlrow. It is the basis of a simple word game, and it is the mode teachers use when demonstrating what string reversal actually does to individual tokens.
Where this is genuinely useful
Flipping line order is the workhorse. Application logs and exports are usually written oldest-first, which is the wrong way round when you are investigating something that just happened. Paste, reverse, and the most recent entries are at the top where you can read them.
Character reversal turns up in programming education more than anywhere else. String reversal is one of the first exercises in every language, and having a reference implementation to check against is useful when your own version is producing something subtly wrong - usually because of how it handles multi-byte characters.
Palindrome checking is the classic case: reverse the text and compare it with the original. Strip the spaces and punctuation first if you want the loose definition, where A man, a plan, a canal: Panama counts.
A note on emoji and accented characters
Naive text reversal breaks on modern text, and it breaks in ways that are worth understanding. Many emoji are built from several code points joined by invisible connectors - a family emoji can be four separate people plus three joiners. Reverse those code points individually and you do not get a reversed emoji, you get several unrelated ones. Accented letters written as a base letter plus a combining mark have the same problem: the mark ends up attached to the wrong letter.
This tool reverses by code point, which handles accented letters and CJK characters correctly and is what nearly every programming exercise expects. Complex emoji sequences are the known exception. If your text is full of them, check the result before relying on it.