ELI5: Explain Like I'm 5

Etaoin shrdlu

Etaoin shrdlu is a phrase from the olden times used in the printing industry. When people used to create newspapers, they needed a quick and easy way to find out which letters or typefaces were the most frequently used, so they could check if everything was correct.

So, if you think about it like a game, the letters in the alphabet would be ranked in order of how often they were used. The most common letter would be given 1st place, the second-most common would be given 2nd place, and so on, until they reached the least-used letter.

"Etaoin shrdlu" is simply a list of those letters in order, starting with "etain," which are the most frequently used letters, and ending with "shrdlu," which are the least-used letters. But, the words themselves don't have any real meaning - they were just chosen because they include all the letters in the list.

To sum it up, etaoin shrdlu is a way of listing the letters in the alphabet from the most frequently used to the least, that was used in the olden days of the printing industry.
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