Case brief info

I’m stuck on a Law question and need an explanation.

The author of the eText states the following on Page 144:

150 words min.

“Few people find it natural to read cases. The language used by courts is often archaic, and the style of writing can make it difficult to comprehend the court’s reasoning. Moreover, the topics discussed in cases are often complex. The most common technique used to impose some order or structure on the confusing world of case law is case briefing.”

What is case briefing? How does it assist in making a case more understandable? What are the origins of the case brief?