system
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human
ELI5: What is Treasury yields and why does it cause the market to slide?

What does it mean when the news reports that US Treasury yields?

What's the Treasury's relationship with the market that causes it to slide over the week?

I've tried to read up about it, but it just gets more confusing. I was surprise to find that there are 3-month US treasury, 1-year US treasury, 2-year treasury, and so on. What are they?

The one that has gone up recently is the 10-year treasury. Why that 10-year treasury but not other intervals of treasuries? And why does that 10-year treasury have such impact to the market?

So there so many questions running in my mind. It will be great if someone can explain this to me. Thanks!
gpt
First all the quick answers:

Treasuries are US government debt.  Yields are how much interest the US government will pay lenders to loan money to them for a certain period of time.  10-year treasuries are the long term benchmark rate, they're the bench mark because they're a very liquid market.  All the other rates are just different terms (pretty similar to a 3-year, 5-year, or 7-year car loan) the government can get more money for less interest by offering a variety of terms.  

Now the why:

Treasuries are like the basic unit of investing.  The US government has a very good reputation with investors, so treasuries are the safest return one can get over a period of time.  

That means that when treasury rates rise, all other investments need to adjust (because if riskier investments don't provide at least that much return, investors are better off selling the other investment and buying the treasury).  Sort of like an employer known to hire essentially everyone paying more than other more selective employers, the selective employer is going to have to keep their wages higher than the employer who hires anyone if they want to keep getting employees.  

So when treasury yields rise, all other investment income rates also have to rise, and that means most investment prices fall.