Role of jargon, What does a 'falling yield' on a 10-year Treasury note mean ?

A common way to specify the difficulty level of concepts is as 'rocket-science' or 'not rocket-science'. Most concepts are usually 'not rocket-science'. But there is jargon associated with each subject, and without knowing the jargon, even simple concepts can seem like rocket-science.

I always liked teachers who stopped and defined/described these jargon terms every time they used them in their lectures. This helped students like me (who did not go over the previous day's lecture/material) follow the lecture without major problems.

It is one of my goals to understand an economics news-article fully one day, so below is explanation about the following economic jargon - 'falling yield' and 'Treasurys'...

From http://finance.yahoo.com/news/Stock-futures-tumble-on-apf-3481581188.html

Interest rates fell in the bond market as investors sought the safety of Treasurys. The yield on the 10-year note dropped to 2.98 percent, the first time it has fallen below 3 percent since April 2009. Its yield is used as a benchmark for many consumer loans and mortgages.

Falling yields are a sign that investors are willing to forgo potential big gains in stocks for more certain, but smaller profits in bonds.

And, what are Treasurys and what are 10-year notes etc ?

Treasury bills (or T-Bills) mature in one year or less. Many regard Treasury bills as the least risky investment available to U.S. investors

Treasury notes (or T-Notes) mature in one to ten years.

Treasury bonds (T-Bonds, or the long bond) have the longest maturity, from twenty years to thirty years.