A rundown is a quick point-by-point briefing on the main facts. Give me the rundown, a quick rundown, the rundown on the situation.
It is informal and means enough to act on rather than everything known. Written as two words with a hyphen it becomes an adjective meaning dilapidated or exhausted, so the same letters do different jobs depending on the space.
1nounrundownA quick point-by-point briefing on the main facts.
“Before the meeting, my boss gave me a quick rundown of the main points.”
rundown is a briefing.
Deverbal from run down.
Etymology from Wiktionary, CC BY-SA