Keep in mind that these are almost always estimates, keywords can be impacted by seasonality (e.g. searches for "halloween" rise in October), and lower-volume queries are often less accurate.
What's a "good" monthly volume? It depends. Typically, a higher number is better, but it also means more competition. A lot of lower-to-medium volume keywords (long-tail keywords) can add up to a lot of search traffic. In the end, the keywords that are right for your business are typically more important than any volume number.
3. Difficulty
In short, Keyword Difficulty is how hard the keyword is for the "average" site to rank for.
Moz's Keyword Difficulty score is heavily influenced by the Page Authority of the top 10 ranking results, weighted by several other factors.
What's a "good" Keyword Difficulty score?
In general, lower numbers are easier to rank for, but your own ranking ability is going to primarily rest on two factors.
A. Your Keyword Difficulty potential
We covered this in Chapter 1, but here's the process again for finding your site's Keyword Difficulty potential:
Enter your site in the Ranking Keywords report of Keyword Explorer
Search using "Root Domain"
Set "Ranking" to 1-3 (keywords you rank highly for)
Set "Volume" to anything over zero (in this case, greater than 11 searches per month)
Sort by "Difficulty" (high to low)
Ignore any branded terms