This article from the BBC had the following lead paragraph:
US swimming star Michael Phelps has admitted to "regrettable behaviour", after a UK newspaper published a photo of him apparently smoking cannabis.
The news elements this lead includes are the who, the what, and the when. The who is Olympic athlete Michael Phelps. The what is admitting to the regrettable behavior. The when is a general time after the newspaper ran a photo Phelps committing said behavior.
This lead tells the reader the most important part of the story in a concise manner. Things are left out of the lead, like the where because it is unimportant to the overall story. The when is left general because the news value is in the event happening, not the day it happened.
The two most important parts of the story are in this lead to draw readers in. The famous athlete and his misdeed are mentioned in the paragraph.
Focusing on some aspects and omitting others conveys the story and keeps people reading.