Given some number how do I know if I got good Loan Package

[Abulele Woldulele]

Yo BP peoples :)

I recently got an loan offer package that details (similar numbers)

Purchase Price, Down, Time,      Monthly Payment 

$900,000         10% down ($90,000)         30 year fixed      $4975/month

$900,000      20% down ($180,000)    30 year fixed   $4474/month

With 10% down I'm getting 4.125% interest, no points.

With 20% down I'm getting 4.000% interest, no points.

I used online-proxies but I found number with "points" included in the estimated loan package (notice how my loan package above has no points). So I wasn't able to compare the actual loan package listed above to what I got online. What are "points", how does it alter the whole equation. Where can I read about it? 

In general, how can I assess if a loan offer is "good", "meh", or "bad"?

What are my biggest bargain points?

Much appreciated is your advise, any inputs, pointers..etc.