Words; w-o-r-d-s, words, lol. Just being silly.
Some don't know the difference between spelling errors and spelling mistakes.
Can you read below:
Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.
The truth is pretty much every fluent English-speaker can read and understand it.
The word-scrambling phenomenon has a punny name: typoglycemia, playing mischievously with typo and glycemia, the condition of having low blood sugar. Typoglycemia is the ability to read a paragraph like the one above despite the jumbled words.