Relax, since unless you are working as a typographer or graphic designer you will probably not have to use lorem ipsum at all. It is essentially nonsense language that serves to show the visual style of a typeface, webpage, or document.
Although it is Latin, English speakers and writers don’t “use” lorem ipsum the way that we do other phrases from that language such as et cetera and ad nauseum as part of everyday communication. Lorem ipsum isn’t really a meaningful phrase, but rather a garbled fragment of a longer Latin text (which includes the clause “qui dolorem ipsum”) written by the Roman philosopher Cicero in the 1st century BCE.
